Car battery -  died because of Corona - how take care of a new one - Page 1
Forum section: electronics / general

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 05:33:09 pm
content: Our Ford Focus had a struggling EFB (Enhanced Flooded Battery), but in Corona time we don't use the car much. Once it couldn't start after a month of nonuse, the second time it was even less.For the new battery I wrote a little script using a programmable PSU and bench DMM that charged the new battery with 10% C (6A), but no more than 14.4 V. So it would gradually draw less current. This process was then stopped when the current dropped to 1% C (600mA).The script uses a "4 wire measument" using the DMM, to correct for a diode drop and some wire resistance. The voltage is now accurate to the mV.Now that this battery is in the car, I would like to ensure that the battery drain was not (also) caused by excessive current leakage. So I like to keep an eye on it by measuring the voltage from time to time. Without much use it is now around 12.39V (after charging, on instalation it was 12.55 V). Which seems low according tohttps://www.varta-automotive.com/bg-bg/%D0%9F%D0%BE%D0%B4%D0%B4%D1%80%D1%8A%D0%B6%D0%BA%D0%B0/charging/how-to-charge-a-car-batteryHowever information on this kind of battery is very sparse. Even the linked page is in most languages replaced by a less technical one.Can someone direct me to a technical document which explains how to determine the charge state. I have driven the car a short while, but looking at the "charge" voltage during idling it was not really charging the battery. The system probably thinks its full. (Previously I've seen it charge during idling). B.t.w. the battery management system of the car has been reset after replacing the battery.

author: zenerbjt
author_rank: Regular Contributor
timestamp: September 17, 2020, 06:47:00 pm
content: It isnt practical to accurately assess SoC of Lead acid by measuring voltage...https://batteryuniversity.com/learn/article/how_to_measure_state_of_charge..how long have you had the battery?...they only last around 2 years dont they?Are you sure your alternator is working. Can you get a current clamp and get someone to rev the car whilst you wath the battery current.

author: Alti
author_rank: Frequent Contributor
timestamp: September 17, 2020, 07:02:23 pm
content: Quotehttps://en.wikipedia.org/wiki/VRLA_battery#EFB_batteryFlooded. Seems that it is same chemistry as FLA battery plus a wank word. So the "Enhanced" means that now you can store your battery in any position. Is it installed in some weird location then, like under driver's seat?BTW, interesting consequences of recent events.I bet you were not the only one that faced same standby/leakage problem.So you decided to drag a battery with you home, to charge it with PSU?QuoteYou can easily determine charge state of FLA battery by measureing the density of the electrolyte. This is super simple, fast and accurate. You need areometer and you can find out state of charge cell by cell (for preventive maintenance). For "enhanced" it seems this key property is no longer available. I have heard there are some FLA methods that involve correlating electrolyte temperature and voltage under some calibrated load but I cannot provide any reference.QuoteThere is no way it could work.And once the EFB is excessively drained, you can toss it to the recycle bin. Upside down.

author: Gyro
author_rank: Super Contributor
timestamp: September 17, 2020, 07:10:13 pm
content: Modern Ford battery management systems can be troublesome. My neighbour had similar problems with his new Ford Galaxy, it kept going into deep standby during periods of little use (Covid again). The faulty battery was replaced under warranty and seems to have solved the issue for now (although it is getting more use).Modern vehicles often deliberately avoid charging the battery at idle (unless its voltage goes down to a low threshold) to reduce load on the engine and improve emissions. Alternators are no longer autonomous, they are 'intelligently' controlled by the engine ECU. Starting the car and leaving it running at idle will most likely leave it in a more discharged state than fully charging the battery and then leaving it.Batteries should more typically last more like 5 years (the better ones are warranted for two). Modern stop-start technology could lead to greater wear, but they should still last a sensible period.

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 07:14:56 pm
content: I did buy a new one, the old one was about 6 years old. On the edge of normal end of life, but with our usage it should have normally live a bit longer.These type of batteries are sealed and the internals can not be accessed. So no DIY density measurements.I think I might indeed buy a current clamp. Any advise on one which can also measure small currents and is not too expensive?Being enhanced also means that they can still throw punches after being discharge til 50%. This type of battery and the better AGM ones are kind of required for stop/start systems (as I understand).

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 07:20:40 pm
content: Quote from: Gyro on September 17, 2020, 07:10:13 pmGood to know, the measurement I did when it was recharging at idling was indeed at a low voltage level, around 11 V - if I remember correctly.

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 07:28:18 pm
content: Quote from: Alti on September 17, 2020, 07:02:23 pmI'm charging the old one out of curiosity of how much capacity it still can hold. It was drained til 9 V. Maybe it has still 30% capacity left. It already accepted 50% of its original capacity.I could make a spotwelder for li-ion batteries out of itotherwise it could function as a jump starter

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 07:36:09 pm
content: Quote from: zenerbjt on September 17, 2020, 06:47:00 pmThis is were it got confusing for me, on the one side VARTA is very explicit about voltages. Don't install if less than.. absolutely charge if less than.. On the other side no good references can be found. Also the voltages are temperature dependend and measuring fully unloaded is not entirely possible when installed in our car.But is would be nice to have some idea what is safe or not, and at the moment VARTA claims the voltage would not be ok, without charging. But either mine is full, or the car has leaked a lot of current in only a day.However doing systematic measurements can give some idea where the discharge is at the discharge curve. (But haven't found a suitable curve yet)

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 08:00:43 pm
content: The funny thing is that the dutch VARTA webpage throws in these voltages as when to charge and the charge curve, but very explicitly says on top of the page: You may not charge EFB and AGM batteries yourself.That's very enhanced indeed!Guess there are "legal based" reasons to do so.

author: IanB
author_rank: Super Contributor
timestamp: September 17, 2020, 08:02:41 pm
content: You can overthink this. Car batteries are pretty robust (they have to be, they live in cars).After my car was parked in the garage without being driven much for a several weeks I noticed the starter motor was getting very sluggish. I measured the battery voltage with everything turned off, and it was 11.8 V. A bit low. So I gave it a bit of a charge with a power supply set to 13.8 V and waited until the charge current was below 0.5 A or so. On disconnecting and leaving to rest for a bit, the battery voltage was up to 12.5 V. Maybe on the low side, but the starter turned rapidly after that.Since then I just keep an eye on the voltage and if it looks like dropping towards 12 V I will give it another top up charge.There's no need to be precious about charging voltages or currents. Do you really imagine the voltage regulation and charge management in the car is that good?

author: ahbushnell
author_rank: Frequent Contributor
timestamp: September 17, 2020, 08:07:28 pm
content: Look at battery universityhttps://batteryuniversity.com/learn/article/charging_the_lead_acid_batteryYou can float charge lead acid batteries. 2.25 to 2.3 V per cell.

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 08:20:52 pm
content: Quote from: IanB on September 17, 2020, 08:02:41 pmIf I could I would do the same. But the thing is: I can't charge the car from home "unattened". It is on a public parking. So I have to take a serious ride with it if its too low. The question is however: when..The 12 V you mention might be a good threshold.But there's still the underlying questing of current leakage. In our situation it would force us to babysit our car battery. (And go driving to make it stop crying.)

author: SilverSolder
author_rank: Super Contributor
timestamp: September 17, 2020, 08:27:10 pm
content: I have the battery Covid symptoms as well. There will always be some leakage... even if it is just the clock on the dashboard!There are so many cheap car charging / maintaining solutions available that it doesn't make much sense to make one.There are small chargers specifically designed to keep unused vehicles alive, e.g. "Battery Tender" is one brand name. Harbor Freight sells one for around $5 that I use on two vehicles, works fine.I have a larger "smart charger" that can be left unattended, and at 10A is powerful enough to run the stereo while I'm working on the car - that's another solution!In your situation, I would make sure the car is driven once every couple of weeks at least, and keep the battery topped up. If you charge it up fully, the car should be able to stand two weeks before needing another charge.

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 08:37:06 pm
content: Quote from: IanB on September 17, 2020, 08:02:41 pmFrom what I've read batteries age faster when charged to slow. Hence the 3 fases, constant current, constant voltage, constant voltage (low). Some advice also trickle charging as fase 4. To float charge a non full battery might even do harm.One solution would be to really disconnect the positive terminal. But I wouldn't know if the battery management system would need resetting then as well. Also some settings would go lost again.. but that is not as an issue as not starting when needed.

author: Monkeh
author_rank: Super Contributor
timestamp: September 17, 2020, 08:39:57 pm
content: Just start and idle the car once a week - roll it back and forth to save the tyres, too.

author: IanB
author_rank: Super Contributor
timestamp: September 17, 2020, 08:41:57 pm
content: Quote from: HendriXML on September 17, 2020, 08:37:06 pmI really wouldn't be inclined to worry about this. Just think about what happens in a car. It gets hot, it gets cold, it gets vibration, it gets drained when parked, it gets rapid charging when you drive fast. Basically conditions in normal use vary wildly. No way does a battery in your car get an ideal three phase charging profile.QuoteHow about one of those solar powered battery maintainers that you put in the window and plug into a lighter socket? Maybe that's what SilverSolder was pointing to? If your car is parked outside all the time this would be ideal. You can trickle charge a lead acid accumulator like this forever without harm.

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 08:44:08 pm
content: Quote from: SilverSolder on September 17, 2020, 08:27:10 pmThat's what we were doing, but after a few times we forgot.. (also thought we were good for a while after a 2 hour drive)Charging a battery takes quite some time. If done by the car at 10% C, it would take 3 hour of driving going from 50% to 100%. For such a long drive some purpose is required

author: Monkeh
author_rank: Super Contributor
timestamp: September 17, 2020, 08:45:41 pm
content: Quote from: HendriXML on September 17, 2020, 08:44:08 pmA 10-15 minute idle once a week is quite adequate to maintain the battery if unnecessary loads are kept off.

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 08:50:12 pm
content: Quote from: Monkeh on September 17, 2020, 08:45:41 pmQuote from: HendriXML on September 17, 2020, 07:20:40 pmThat might not work with the Ford.

author: Monkeh
author_rank: Super Contributor
timestamp: September 17, 2020, 08:53:25 pm
content: Oh, I missed that it has a defective charging system by design. Apologies.

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 08:59:27 pm
content: I think I need a current clamp, that would give an idea what is lost. (+ only 0.3% self discharge / month.)It only should be sensitive enough, doesn't need to be very accurate in this case,Then we would know how long of a ride is needed, to keep the balance ok.

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 09:00:01 pm
content: Quote from: Monkeh on September 17, 2020, 08:53:25 pm

author: Gyro
author_rank: Super Contributor
timestamp: September 17, 2020, 09:47:20 pm
content: Quote from: Monkeh on September 17, 2020, 08:53:25 pmActually, it isn't too recent a feature. On our old 12 year old Astra you could start the engine, put the headlights on, reverse out of the drive at more or less idle and then suddenly see the headlights brighten when pulling away (not like an old dynamo, a sudden one way step change). The charging system was fine, never had a flat battery or premature failure. If you watch visitors pulling away in the dark, most cars do it, even with headlamp and heater blower load.Removing the drag of the alternator eases starting too.These days we have instant engine starting from a 240V three phase 8kW hybrid starter-generator (and the lights and aircon are the same whether the engine is running or not)

author: Alti
author_rank: Frequent Contributor
timestamp: September 17, 2020, 09:53:15 pm
content: Quote from: Monkeh on September 17, 2020, 08:53:25 pmIt is a bigger version oftamagotchi.

author: IanB
author_rank: Super Contributor
timestamp: September 17, 2020, 10:10:44 pm
content: Quote from: Gyro on September 17, 2020, 09:47:20 pmI doubt that this is anything more than incidental. The output voltage of a basic alternator/generator will be proportional to speed, so when idling the voltage will be low. When revved the voltage will be really high. So at idle the battery voltage alone will give a lower brightness. When you rev the engine the system voltage increases to 14 volts or more and the lights get brighter. There is no need for any special design to produce this behavior. It was probably the same in the 1950's.

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 10:11:33 pm
content: Quote from: Gyro on September 17, 2020, 09:47:20 pmMost (to my knowledge) car airco's are driven by the car engine (not electrical).

author: Gyro
author_rank: Super Contributor
timestamp: September 17, 2020, 10:13:53 pm
content: Not when you drive a hybrid. The compressor is 3 phase electric and runs from the high voltage battery too.Edit: Sorry, I digress.

author: Gyro
author_rank: Super Contributor
timestamp: September 17, 2020, 10:20:22 pm
content: Quote from: IanB on September 17, 2020, 10:10:44 pmNo, even back then (2006) the Astra alternator was under ECU control (according to the service manual anyway). Alternators are quite capable of producing a decent 14V charge voltage at idle, unless they're told not to.

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 10:31:19 pm
content: Quote from: Gyro on September 17, 2020, 10:13:53 pmBut I guess not a 60 Ah battery.In that case more even more than a month the remote control and clock can drain, and keep car functional. Me jealous

author: The Soulman
author_rank: Super Contributor
timestamp: September 17, 2020, 10:43:14 pm
content: Quote from: HendriXML on September 17, 2020, 08:59:27 pmI have this:https://www.reichelt.nl/zangenadapter-ac-dc-bis-60-a-peaktech-4250-p288855.html?&trstct=pol_11&nbc=1https://www.eevblog.com/forum/testgear/peaktech-4250-acdc-current-clamp-teardown-and-repair/And also these:https://www.conrad.nl/p/voltcraft-ms-4s-meetadapter-mini-steekzekeringsstekker-banaanstekker-4-mm-zwart-rood-122232?WT.mc_id=gshop&gclid=CjwKCAjwkoz7BRBPEiwAeKw3q8MqxL1oHDaaTauLiUkz-jJjgceDb_h_fWxE4gevugtYrNNqwpXkGhoCHggQAvD_BwE&gclsrc=aw.ds&tid=9774089998_102830953594_pla-928590597752_pla-122232&WT.srch=1&vat=true&insert_kz=8JUsed the last one to find out the booth light stayed on due to a miss-aligned switch..If you feel like driving to Smilde we can have a look.

author: sokoloff
author_rank: Super Contributor
timestamp: September 17, 2020, 10:50:33 pm
content: Quote from: Gyro on September 17, 2020, 10:20:22 pmTrue. Note that "under ECU control" just means the field current comes from the ECU, which can thereby act as a smart voltage regulator, cutting the field current to zero whenever it wants to "shut off" the alternator.I have to imagine that ECU programmers would be smart enough (even in 2006) to produce field current even at idle if the system voltage dropped below 11.5 V or so.

author: HendriXML
author_rank: Super Contributor
timestamp: September 17, 2020, 11:45:23 pm
content: Quote from: The Soulman on September 17, 2020, 10:43:14 pmThat fuse probe thingy is exactly the product I thought I had to make myself if further diagnostics were needed. Which would be very time consuming..Is the low current function of the Peaktech ok now?

author: CatalinaWOW
author_rank: Super Contributor
timestamp: September 18, 2020, 01:22:50 am
content: I agree with IanB. Don't overthink this. A constant voltage source is all that is needed to keep these batteries in as good a shape as they can be after normal automotive usage. I have one vehicle that has an intermittent 500 mA parasitic load that I have been chasing for a few years without success. If the car is left for a week or two there are fairly good odds the battery will be flat. A simple under $20 dollar battery maintainer has completely resolved the problem, other than the nuisance of hooking it up. As suggested previously a dashboard mounted solar panel should solve your problem of no access to mains.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 18, 2020, 03:07:34 am
content: If you park outdoors, get a small solar panel.If you park in a garage, connect an unregulated (linear) 12V wall wart to the battery and use a cheap plug in timer to turn the wall wart on and off. 15 minutes per day would be a good starting point, some voltage checks will let you fine tune it.Quote from: HendriXML on September 17, 2020, 10:11:33 pmIf we exclude EVs and plug in hybrids, ultimately everything is powered by the engine.

author: HendriXML
author_rank: Super Contributor
timestamp: September 18, 2020, 07:58:29 am
content: Quote from: CatalinaWOW on September 18, 2020, 01:22:50 amGee, 500 mA if it where continuous, that would mean 2,5 day going from 100% to 50%. Without "support" kind of a nightmare!Having it solar powered might indeed be the solution. Leaving it outside the car would be no option, inside the car it better not look too expensive. Charging via a 12V socket in the car would be an option. (One of them never get disconnected after engine shutdown). Besides a fuse nothing else is expected between the socked and the battery I think.

author: HendriXML
author_rank: Super Contributor
timestamp: September 18, 2020, 08:12:41 am
content: Quote from: NiHaoMike on September 18, 2020, 03:07:34 amNice vid!

author: Gyro
author_rank: Super Contributor
timestamp: September 18, 2020, 09:03:47 am
content: Quote from: NiHaoMike on September 18, 2020, 03:07:34 amAbsolutely. It's merely a matter of when that power is available - whether it is available 'time shifted' from when the engine is actually running. This brings the useful benefits in terms of economy (and sometimes comforts).

author: The Soulman
author_rank: Super Contributor
timestamp: September 18, 2020, 12:11:09 pm
content: Quote from: HendriXML on September 17, 2020, 11:45:23 pmIt can resolve miliamps but accuracy isn't great that low.Also it is very sensitive to other magnetic fields, proper orientation and placement is critical.It also drifts after zeroing, zero for 10 seconds = measure 10 seconds.Mostly use it for whole amps, great tool for quick diagnosing battery circuits etc.For your car leakage current searching I'd use those blade fuse adapters (there are at least two different sizes).Or if you are brave, wire a normal current measuring dmm in series with your battery and pull fuses one by one to find the circuit where the current is going.But don't turn anything on in the car tho, as it will likely fry the dmm fuse immediately.Therefore I've used a non fused dmm for that, did I mention brave?

author: SilverSolder
author_rank: Super Contributor
timestamp: September 18, 2020, 12:38:26 pm
content: Another way to do it is to put a shunt resistor in series with the battery, and measure the voltage across it - less likely to burn your meter!

author: SeanB
author_rank: Super Contributor
timestamp: September 18, 2020, 01:08:50 pm
content: Funny enough just replaced the battery today, lasted 2 years, which is typical of cheap batteries, so I went and got one that is fresh and with a 2 year warranty, so it might do 3 years. Regular flooded, and i do check the electrolyte level at least every second month, so I see the loss with time, and the loss is what kills most other batteries as they have a stick on cover over the plugs, so no ability to check. My one tested good, but with a high self discharge rate, so likely the plates are bridged internally by sludge, as it did respond to charging well and went into float, but even a half hour of sitting was resulting in sluggish starting as it dropped down, double whammy of less active material on plates and the debris drawing current internally.

author: Monkeh
author_rank: Super Contributor
timestamp: September 18, 2020, 01:16:13 pm
content: I haven't had a decent battery last less than 5 years so far, and most of them come with 3-4 year warranties. Cheap ones are a false economy.

author: drussell
author_rank: Super Contributor
timestamp: September 18, 2020, 01:40:17 pm
content: Quote from: Monkeh on September 18, 2020, 01:16:13 pmExactly! I usually get 10 years out of mine before a cell shorts due to sloughing or something, but I'm careful and maintain them properly. I used to use Sears DieHard in the 80s and 90s, then switched to Intertstate MegaTron Plus for car starting batteries and SRM series for my deep cycle needs.If you want maximum life and are willing to actually watch your electrolyte level manually you can usually get twice the life out of a standard, old-school removable-cell-plug type rather than those "Maintenance Free" pieces of crap.... of course, for those drivers who don't even open the hood between battery changes, they're probably better off getting 3-4 years out of a set-and-forget maintenance free... but those are the same folks who don't ever change their oil, let alonechecktheir oil regularly to see if there is even any in the crankcase...

author: f4eru
author_rank: Super Contributor
timestamp: September 18, 2020, 05:42:30 pm
content: Chargin it one ca month during one night with a floating charger -> perfect.

author: HendriXML
author_rank: Super Contributor
timestamp: September 18, 2020, 09:25:40 pm
content: We took the car for a drive today. The good news: the battery voltage went up: 12.60, so it is charging jay!The disturbing new is that it had a temporary shutdown of all electronics after breaking just before arriving. (The whole dashboard, speedo meter etc) The engine kept running though.My best guess is that the battery moved a bit. (I measured it has some 5 mm freedom of movement in its container. Will solve that). And that this movement made the contact resistance of one connector high.I did not sand the connectors (poles?) because the clamping force would be very high. But after this experience this needs to be reassured, I think. Maybe someone has another suggestion. If is was a "loose contact" causing it, I would find it surprising. But what else could it be.. Could a battery shock cause a voltage drop?

author: SilverSolder
author_rank: Super Contributor
timestamp: September 18, 2020, 09:37:55 pm
content: Quote from: HendriXML on September 18, 2020, 09:25:40 pmYes, sediments dropping to the bottom of a cell can cause internal shorts and temporary voltage drops. - If it has been allowed to stand around for a while with very low charge, it will be broken and have severely reduced capacity.Basically, once a battery starts to "misbehave" the only real cure is to replace it. Then make sure the new one is topped up every 2-4 weeks with a charger, if you are not using the car much. That should see you right.

author: HendriXML
author_rank: Super Contributor
timestamp: September 18, 2020, 09:49:40 pm
content: Quote from: SilverSolder on September 18, 2020, 09:37:55 pmAfter receiving the new battery the first thing I did was a voltage measurement to see wether was worrisome, but it was fine. Also it didn't take long too top it up to full. But I'm still not sure what the constant voltage fase of the charging should be 14.4 or 14.7 of this type of battery.https://www.rotronicsbms.com/pub/media/resources/images/image/c/t/ctek_pro120_user_manual.pdfThe above document discusses it, but does not provide EFB type information.So I guess the situation you mention doesn't apply in this case.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 18, 2020, 09:58:05 pm
content: Quote from: HendriXML on September 18, 2020, 09:49:40 pmSorry, I somehow missed that this was already a new battery. - So has the new battery ever been subjected to being discharged and left standing? (14.4 is a good target voltage, not much benefit in going above 14.5)New batteries can have faults too... Is there a warranty?Accepting a charge quickly can be a sign of a bad battery, funnily enough. In other words, if the battery is discharged down to 11.2 volts, and it very quickly gets charged back up to 14.4, that is a red flag.If the battery is OK, there can be problems with the fuse box, or where the ground strap attaches to the car, and many other exciting things. But the first thing to eliminate (and the most likely suspect) is the battery.

author: maginnovision
author_rank: Super Contributor
timestamp: September 18, 2020, 10:04:28 pm
content: Personally the first thing I'd check is the terminals are tight on the battery. 9/10 times I see a car die then come right back it's loose battery terminals on the posts. Especially troublesome if the terminals and posts weren't cleaned when installing the battery.

author: HendriXML
author_rank: Super Contributor
timestamp: September 18, 2020, 10:10:02 pm
content: The delivery voltage was 12.58 V after which it received I think an 30..60 min of charging. So that seem ok. I did enhance my script to record how much (Ah) the (old) battery can receive. (I think it still in usable shape - but not for the car, the voltage is Slowly climbing)

author: HendriXML
author_rank: Super Contributor
timestamp: September 18, 2020, 10:11:36 pm
content: Quote from: maginnovision on September 18, 2020, 10:04:28 pmGood to hear. This is what I hope for! (But they seem not loose, but one is not accessible yet)But also a bit embarrassing for an electronic enthusiast...I did tighten them a lot, so it would be the not cleaned part.I think "metal wool" would be the best choice for a clean up? In a way it has now become important to ensure it is optimal.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 18, 2020, 11:19:36 pm
content: Quote from: HendriXML on September 18, 2020, 10:11:36 pmA small wire brush is good. You can even get special wire brushes that "fit around" the battery posts to clean them... but that's a luxury!E.g.https://www.amazon.com/Schumacher-BAF-BI-Terminal-Cleaning-Brush/dp/B0060YHP62

author: HendriXML
author_rank: Super Contributor
timestamp: September 18, 2020, 11:45:49 pm
content: Buying such a luxury would delay the project, can't let that happen.At the moment I think the battery might have some issue which responded to a shock. Maybe a temporary short.These screwed connections are soo tight and not under strain. I can't imagine that a small movement of the battery would effect the positioning let alone the resistance. But cleaning the connection is the first step to diagnose this. However these rare symptoms are the hardest to get a grip on.But it would be dump if the airbags didn't pop in a crash because of such a problem.Doing a 4 wire resistance measurement on the connectors before cleaning might give some insight wether there was a problem. But taking the bench dmm outside is a bit of a hassle...

author: HendriXML
author_rank: Super Contributor
timestamp: September 19, 2020, 12:04:12 am
content: After some thinking, will put on the "grant lights" as we say in dutch and measure the voltage drop over the connectors. With 0.1 mV resolution of the handheld MM that would give even better insight.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 19, 2020, 12:33:49 am
content: Quote from: HendriXML on September 19, 2020, 12:04:12 amIf you do that while someone starts the car, it might tell you something. Starting the car will pull several hundred amperes out of the battery, if there is any resistance, you will see a voltage drop!

author: drussell
author_rank: Super Contributor
timestamp: September 19, 2020, 12:35:49 am
content: Clean both battery terminal connections properly and re-connect, for sure, but also check the ground connections at the other end of the cable, usually there will be two wires, one running to the engine block itself to take most of the starting current and another going to the frame. It sounds like you're ending up running with the grounding of the frame mostly through the engine block, possibly just through the exhaust system, etc. This is a very common oversight and will cause all sorts of weird, random problems, and certainly sounds like precisely what you're seeing when you were breaking and then lost power to the body electronics.In the past few weeks I fixed that on two cars, one was a 90's Intrepid or Concord or one of those thingies, the other was an old '68 Imperial with a 383. (Well, I didn'tfixthat one, just pointed out to the owner what the issue was since they had no battery -> firewall wire.)If you measure the voltage from the battery - terminal to a good ground on the frame, I suspect you'll see a volt or more drop right now. I'd be willing to bet it's a bad frame ground somewhere. They will look fine, but undo it anyway, wire brush it off and re-connect. I highly suspect that will solve your problem.Your old battery would probably still work fine for another year or two also, if you just trickle-charge it for a few days, bring it all the way up to about 15 volts. for a couple hours.

author: HendriXML
author_rank: Super Contributor
timestamp: September 19, 2020, 12:49:16 am
content: Will do that. But as you said, I will take some measurements first. At this moment some testing results can be preserved. Will Also use the min/max function of the MM and do some "cable pulling". The connection I don't completely trust is the one to the body, as you said. Why?In the procedure I followed that way the last one to connect. But it kept sparkling while screwing it on while using light pressure. The next time I would take another connection as last just for that reason.Those post connections are fine connections right away.

author: Monkeh
author_rank: Super Contributor
timestamp: September 19, 2020, 12:51:23 am
content: A bad ground seems reasonably unlikely - a Focus like this is quite a modern car, and to my knowledge there's not a lot of salting going on down in NL..

author: HendriXML
author_rank: Super Contributor
timestamp: September 19, 2020, 01:11:26 am
content: The connection I mention is the "start" of the grounding, so it still might be. But I would still be surprised if it was faulty. Its a bolt into the metal body, the screwing and fastening would deal with corrosion IMO. But I will take measurements to validate the current situation. Then I'll optimize it to the max. Then it will be waiting for it to happen again (or not). Then it might be the battery internals.Can the body electronics function on just the alternator and a broken battery connection or would the voltage get too high? (Is it regulated?).

author: Monkeh
author_rank: Super Contributor
timestamp: September 19, 2020, 01:18:04 am
content: Why would you undo that end? You should only need to deal with the battery terminals directly..Yes, it will all run without the battery, technically - I've just recently had to do that on a Honda with a dead battery (sure, it was there, but at 0.8V open and charging at 15mA it may as well not be). It's regulated, but there's a lot of ripple and if the alternator goes bad there's nothing meaty enough to clamp the voltage without a good battery in place.

author: HendriXML
author_rank: Super Contributor
timestamp: September 19, 2020, 01:32:08 am
content: Quote from: Monkeh on September 19, 2020, 01:18:04 amMaybe I was not clear, but nothing gets undone, only cleaned and reapplied.But if they're hypotheticaly ok, then the next possible fault to check is probably the battery. In that case was it a short or a opencircuit what caused it. If an open circuit would not result in the body electronics to shutdown. Then it could be a short, taking the alternator voltage with it. (Not saying that that is likely)

author: HendriXML
author_rank: Super Contributor
timestamp: September 19, 2020, 01:44:41 am
content: I think you mean why it was unscrewed in the first place.... I followed the procedure of a Haynes instruction video. In our car the negative terminal is unaccessible at first. To get access to it the battery must get out or moved to the front after removing the air filter assembly... It is a hassle..https://youtu.be/HidL_hOkDhY

author: Monkeh
author_rank: Super Contributor
timestamp: September 19, 2020, 01:54:45 am
content: Oh for the love of fu-, err, Ford.Well, that's special. Anyway, your problem is going to be one of the three connections you had to undo, so get it back out and redo it. Don't be scared of a little sparking.

author: HendriXML
author_rank: Super Contributor
timestamp: September 19, 2020, 07:01:02 am
content: Quote from: Monkeh on September 19, 2020, 01:54:45 amI love the sparksBut hearing things go on and off on and off.., which draw a quite some startup current could give voltage spikes trough induction. So better to have it for a second then tenths of seconds. (It takes long to screw in the body connector)

author: HendriXML
author_rank: Super Contributor
timestamp: September 19, 2020, 07:51:25 am
content: So I did some Quick measurements, the connector which is now unaccessible is skipped.If I turn on some power users the positive post clamp does not have a significant voltage drop.The body connection drops some 2 mV. But thats harder to measure correctly.I'm charging the old battery at home in sessions without clamping, just 2x coper wireloops around the posts and they also only drop a mV at 2 A.So I'm still having a hard time believing "loose connections" will be the cause in this situation. I will optimize them, but my guess is that the battery momentum/sudden stop in the battery box has something to do with issue.There where also no voltage drops using the min/max measurements and pulling cables/moving the battery.But seeing how easy it is to move the battery those 4 mm of play it has...that needs solving as well.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 19, 2020, 11:48:25 am
content: The cable itself could be a problem too, i.e. where the cable mates to the connector that bolts to the battery can corrode inside, causing intermittent connections.Another thing: once you have fixed all the issues and cleaned up the connections, always use a Battery Terminal Protectant to make sure connections stay good for years with no corrosion.For example,https://www.amazon.com/DeoxIT-Battery-Cleaner-Protectant-CL-BCP-04/dp/B078JT8K1LThere are many other products. Many of them come in aerosol cans, but I think the aerosols make a mess everywhere so I prefer the type that is brushed on.

author: Monkeh
author_rank: Super Contributor
timestamp: September 19, 2020, 12:20:52 pm
content: "battery terminal protectant" - your choice of any old grease you have on hand. Nothing specific is needed..

author: HendriXML
author_rank: Super Contributor
timestamp: September 19, 2020, 12:28:22 pm
content: I was very generous when putting on vaseline, so there first some cleansing to do.The battery will get a silicone baking mat underneath, so no more sliding. But probably hard too slide in as well.(Once the negative terminal with its monitoring sensor is on, the handle cannot be used anymore.)

author: SilverSolder
author_rank: Super Contributor
timestamp: September 19, 2020, 12:30:46 pm
content: Quote from: Monkeh on September 19, 2020, 12:20:52 pmI think the specific products tend to leave a less sticky surface, and often have a pretty red color!The Deoxit product has corrosion removing properties as well as protective properties, which makes it different from a protection-only grease.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 19, 2020, 12:32:01 pm
content: Quote from: HendriXML on September 19, 2020, 12:28:22 pmThe battery should be bolted down so it can't slide - is the fastener tightened all the way? Many Fords have a plastic "wedge" with a bolt in the middle that clamps the base of the battery against the opposite side of the tray...

author: HendriXML
author_rank: Super Contributor
timestamp: September 19, 2020, 12:34:54 pm
content: It was tightened all the way. No wedge to bee seen. The silicone mat is also for the spacing, it only needs a mm more for some clamping force. Under the bracket I'll place some silicone mat as well.

author: drussell
author_rank: Super Contributor
timestamp: September 19, 2020, 12:36:12 pm
content: Quote from: Monkeh on September 19, 2020, 12:51:23 amYou would be surprised!I see this all the time, even in cars only driven in the summer here, so salt's not necessary. The connection might LOOK good, but that last one, the Intrepid (no, can't be that, it's smaller, a Sebring maybe?), or whatever it was, I cant remember... it's red... is only summer driven, the guy spends the winters down south in his RoadTrek camper van motorhome thingy.The connection LOOKED fine, but there was a couple volts of voltage drop across it. Even when I unbolted it, it didn't' LOOK corroded at all, but wire brushing it up real well and re-connecting it made it 0v. The complaint was intermittent dashboard lights dimming/flashing, random idiot lights and occasional other random things like stalling at a light.Customer had had a new battery installed (even though nothing was wrong with the old one) and then alternator replaced (again, nothing would have actually been wrong with it) by shops that apparently have no electrical system knowledge. It took me all of 5 minutes to find the fault and fix... I already had a hunch just by the symptoms when he called me, and sure enough, that one little bolt about 8-10" from the battery with about an 8ga wire to that one frame bolt was the culprit.We then test drove it down to the auto parts store to get a battery disconnect so he can easily leave the battery disconnected over the winter instead of it being really low by springtime or having to leave it on a maintainer once I explained to him that they make these little $15 doodads just for that purpose. He was happy as a clam. (Other than lamenting the fact that he'd wasted money replacing a perfectly good battery and alternator without changing his issue one iota.)

author: drussell
author_rank: Super Contributor
timestamp: September 19, 2020, 12:41:02 pm
content: Quote from: Monkeh on September 19, 2020, 12:20:52 pmIndeed. Wheel bearing grease or chassis lube grease works just as well.Quote from: SilverSolder on September 19, 2020, 12:30:46 pmSome of them are even redYou should be cleaning all corrosion off first anyway, and not that a purpose-built battery-terminal grease isn't good, it's just unnecessary to go out and buy some just for this purpose.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 19, 2020, 12:50:46 pm
content: Quote from: drussell on September 19, 2020, 12:41:02 pmI have the special battery grease (several types, even), but no chassis lube or wheel bearing grease!There isn't a grease nipple to be found on any of the vehicles I regularly deal with...

author: drussell
author_rank: Super Contributor
timestamp: September 19, 2020, 12:53:25 pm
content: Quote from: HendriXML on September 19, 2020, 07:51:25 amIt pretty muchhasto be a bad connectionsomewhere. If moving the battery 4mm causes it, then it's probably a broken cable, often right where the cable enters the battery terminal clamp itself. If it's not there, thensomewhere, by your symptom set.... If it's not the frame ground or its cable, thensomewhere!Does this car have a-distribution block for some things instead of using the frame? My Dakota has pretty much all the wiring, certainly anything that even remotely connects to the computer, grounded back to the power distribution block by individual black wires instead of just going to the frame. This block is below the positive block with all the fuses and relays in the underhood fuse panel.I don't know much about the most recent modern Fords, haven't done anything on very many of those for years. The last ford I recall was one of those Contour / Mystique things with the alternator located essentially right behind the front bumper, in the wheel well, where it gets constantly flooded with road grime and salt wash... Nice work, Ford.

author: drussell
author_rank: Super Contributor
timestamp: September 19, 2020, 01:05:19 pm
content: Quote from: SilverSolder on September 19, 2020, 12:50:46 pmLOL...There arealwaysuses for a tub of chassis grease, things like wheel stops can benefit from a dab, for example, and even general purpose around the garage and house, although other products can often be used too, of course.Too bad everything is those sealed hub units, etc. these days. Sure you usually get reasonable service life on a car then just replace the whole sealed unit, but especially trucks that are really used and abused, it iswaynicer, at least in my world, to be able to just spend the 5 minutes to clean, inspect and re-pack the tapered roller bearings on a wheel hub at every brake service interval, and only have to pay like $7 for a new inner and $13 for an outer bearing and race set if one starts to go bad instead of having to replace an entire expensive hub assembly, especially on trucks with 6-8 lugs they get very pricey, as soon as you start to get any wear.In the van, a set of front bearings is one of the things in my little dish-tub of spare parts that I carry with me for highway trips. I keep things like that on hand so if I'm changing brake pads and notice any pitting on a bearing or something, I just grab the ones from the bin, then buy another spare set at my earliest convenience... Ditto for virtually all "wear-item" parts. I like to already have them on hand.But, then again, I'm certainly not "normal".

author: Gyro
author_rank: Super Contributor
timestamp: September 19, 2020, 01:27:51 pm
content: Nothing beats Vaseline for battery contacts, it melts into the seams of the connection and excludes oxygen and moisture. There's no point in using anything messier to clean up or more expensive.There's certainly no point in forking out on Deoxit.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 19, 2020, 01:28:29 pm
content: Quote from: drussell on September 19, 2020, 01:05:19 pmSounds like you put a lot of miles on your vehicles!I don't think I've ever managed to wear out a set of wheel bearings, even my highest mileage car (a 15 year old Ford Escape with 220K miles) has its original bearings, running smooth. Maybe I just don't drive them hard enough?Regarding the battery grease: The benefit of the dedicated pretty red protectants is that they dry after applying them, so you don't get messy fingers or messy cables every time you attach a charger or whatever, and they don't attract dust or dirt. I connect a charger a lot, because (1) I like using the car stereo while I work on them (the most ridiculous stereo uses nearly 100amps peak, LOL), and (2) my vehicles don't get driven enough during these corona times, so they need regular top-up charges.(Note: the DeOxit product doesn't dry, it stays wet to keep killing corrosion - makes it a permanent cure for trailer connectors or any other connector that regularly corrodes)

author: drussell
author_rank: Super Contributor
timestamp: September 19, 2020, 01:54:46 pm
content: Quote from: SilverSolder on September 19, 2020, 01:28:29 pmIndeed... the van is about to turn over to 00000 again, it's at 967xx right now. That won't be the first time I've been driving it when it turned 00000, and it won't be the last!It won't do it on this next trip to the lake but it will by the next time when I go out there at thanksgiving since it's 1400+km round trip...This is Km, though, not miles.QuoteThe van's bits are mostly over 40 years old and it's been 26 years since I had everything apart for a complete re-do (that's when I beefed up the engine another notch with the 2.02 intake valves, even more ridiculous camshaft and more extreme porting, the bigger 1-3/4" headers, etc. Re-painted the engine bay, entire floor of the interior, etc. The transmission is a youngling compared to the rest of the van, it's a 1990 4-speed A518 I put in there about 25 years ago to add the overdrive instead of the original 727 3-speed. With the 3.55 axle on there, it can tow pretty much anything. With the original 2.76 I have on there right now, it basically just idles down the highway and I can go all the way to the lake on a single tank of fuel, (a 7-8h drive through several very steep mountain passes) even with the crazy 3/4 race engine in there. I absolutely love it.It's way overdue for a freshening, though... I'm already trying to source all the lower body panels that have rust on them so I can even fix up the body properly, welding in new metal when I tear the whole thing down again this next time.It was still good last time but has 26 more years of salt grime eatin' away at it since. The body was originally white and had been repainted white at least once and then re-painted red before I bought it decades ago. I still haven't got around to doing what would have been the "last" of the body work and painting it yet... By now, it needs pretty much all the lower edge bits replaced, they always rust there, but it's a 40 year old daily driver, what do you expect?QuoteYeah, mine draws about 60A continuous at my typical highway listening levels (that would be "concert level") with peaks up into the hundreds, hence the need for a dedicated alternator.I hit 136 dB in competition "back in the day", but typically only listen in the high 120s, probably usually 125-127 dB while hurtling down the highway. It's my wildlife deterrence system... Yeah... That's it...QuoteYeah, trailer connectors are bad for that, for sure...Edit:Corrected missing quote tags & typo.

author: HendriXML
author_rank: Super Contributor
timestamp: September 19, 2020, 04:43:16 pm
content: I've completed the task of reconnecting the terminals and putting a silicone mat underneath the battery.Rock solid now.The state of the posts were free from corrosion, also the clamps were in great shape. I still give them some cleanup. But I'm absolutely sure this could not have given problems.However the connection to the frame body, is of a strange design.A flat piece of metal is screwed onto a location that is completely painted. The current thus goes through the welded nut on the other side, bolt, and a washer (then connecting the flat piece of metal).The total contact area is very small for the type of conductivity the ironlike metal has. I just had to scrape the paint away...There isn't any other ground connection (besides maybe trough the battery monitoring sensor) from the battery.Hopefully it is now fixed. I now also didn't connect that one last. All that sparkling could create spots of corrosion as well.

author: drussell
author_rank: Super Contributor
timestamp: September 19, 2020, 04:49:28 pm
content: Quote from: HendriXML on September 19, 2020, 04:43:16 pmYup...Those (very important) connections to the frame are often absolutely terrible, right from the factory.You've probably fixed it now, though!!

author: tom66
author_rank: Super Contributor
timestamp: September 20, 2020, 07:21:18 am
content: Dodgy grounds reminds me of an interesting fault on my old Peugeot 206.When you indicated left the ABS light would sometimes come on accompanied with an ESP system warning too!Turned out that the ground for the light indicator cluster was bad and the car could not detect the function of the brake light correctly - it was designed to flash the brake lights under hard, ABS-assisted braking.Fixing the ground, which was on painted metal, resolved the issue. It had barely any contact area from the factory. Perhaps they are concerned about corrosion?

author: HendriXML
author_rank: Super Contributor
timestamp: September 20, 2020, 09:08:36 am
content: Maybe it is too "expensive" to locally remove paint. I'll protect it with vaseline and it probably will be good. Otherwise better to have a known issue that needs cleaning every few years than a bad ground in the DIY case.If you compare such connection to the one on the battery it is almost hilarious. It handles the same current.

author: drussell
author_rank: Super Contributor
timestamp: September 20, 2020, 09:37:03 am
content: Quote from: HendriXML on September 20, 2020, 09:08:36 amWell, not really. The starter motor current goes through the big, fat ground wire that goes directly to the engine block, as does the charge current from the alternator. It is still extremely important, though...Things like your headlights, heater motor, rear defrost window grid and everything else in betweendoflow through that tiny connection... which is why it has to actuallybeconnected, not justappearto be somewhatcloseto connected like they often seem to do at the factory.This can actually cause severe damage in some bizarre edge cases like where the frame is ending up being grounded through drivetrain bearings. Sending significant current through a rotating ball or roller bearing will literally eat it away with tiny sparking and welding essentially doing EDM, (electrical discharge machining) munching away at the bearing causing rapid premature failure.Edit:Like, imagine you have a conventional RWD vehicle, and you disconnect that frame ground from the battery, and instead connect a big fat wire from your rear axle housing to the frame. The engine block is well grounded with the big fat main ground wire, but now all your body ground current is flowing back through your rear axle housing, through the bearings, through the ring and pinion, up the driveshaft through the U-joints, through the yoke into the output shaft bushing and any nearby bearings, etc. in the transmission before actually returning to the engine block ground. This isnotgood.Now, on the other hand, if you look at a fairly late model Honda Civic, the entire thing,includingstarter motor is only connected via a wee, tiny little 8ga wire. Good thing those things have little plastic toy motors in them or they would never even manage to start in the winter.

author: HendriXML
author_rank: Super Contributor
timestamp: September 20, 2020, 11:13:55 am
content: Quote from: drussell on September 20, 2020, 09:37:03 amIn the FoFo the only fat cable goes to that point, there isn't any other.

author: drussell
author_rank: Super Contributor
timestamp: September 20, 2020, 03:08:49 pm
content: Quote from: HendriXML on September 20, 2020, 11:13:55 amOh, god... so it's as bad as the Civic then, except maybe with a fatter wire.The one on the Civic is ridiculously TINY. We're talking about less than a foot of wire in each car and they skimped on copper all the way down to 8ga. I couldn't believe it when I saw that.Had to clean the posts and ground on one about a year ago for the car wash. Customer had brought in the Civic for a full detail job and the guys at the car wash couldn't get it starting reliably, even after putting the charger on it, was still bein' all flakey so they called me like they do any time they might have messed something up (often it's getting water into power window switches when they're scrubbing the interior, etc.) but it's rarely something they totally caused that day, like this Civic obviously wasn't charging right before they came in to have it cleaned, washing the engine bay probably just made it slightly worse. (Later the customer even said it hadn't been working right, thought they needed a new battery.)All it needed was that frame ground cleaned, paint scraped and connected up properly and it's better than factory.Cleaned the battery posts and clamps too for good measure, of course. The car was returned to the customer with the added bonus of the charging system being fixed, now knowing theydidn'tneed a new battery right away, and it didn't cost them an (extra) dime. It was still something like a $250 thorough clean & detail job, of course.

author: drussell
author_rank: Super Contributor
timestamp: September 20, 2020, 03:17:50 pm
content: Quote from: Monkeh on September 17, 2020, 08:53:25 pmIndeed! Apparently on multiple fronts.(Although the lack of charge at idle on many cars, especially right after starting is simply the battery accepting all the charge current the alternator can produce at idle, evenwiththe field commanded on full, so the voltage never gets up to what we'd consider normal "charge" voltage. Most of the time, on most vehicles, it probablyisactually slowly charging in most cases as long as the rest of the electrical draw is below the alternator output.I'm sure there are some where the computer delays application of the field, though, and they've also often essentially gone to the trick that hot rodders sometimes use free up a couple HP by underdriving the alternator right from the factory. I guess it workswell enough, I suppose.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 20, 2020, 04:00:19 pm
content: Carsmustcharge at idle, if you think about it. Otherwise they would just drain out and stall in congested city traffic, sitting with the A/C or heater on!

author: Alti
author_rank: Frequent Contributor
timestamp: September 21, 2020, 08:17:45 am
content: Quote from: HendriXML on September 20, 2020, 11:13:55 amOk, the fact is that the starter needs to be connected between negative and positive terminals of the battery. There must be some continuous path from negative terminal to engine block. You nave to take care of all the connections in series, not only the one from negative terminal to car's body.

author: drussell
author_rank: Super Contributor
timestamp: September 21, 2020, 11:58:37 am
content: Quote from: Alti on September 21, 2020, 08:17:45 amTrue, but his problem wasn't lack of starter juice, it was intermittent poor charging and body electronics dropout.The "bad" connection to the frame was obviously making decent enough connection most of the time, just not always. It's still not a bad idea to find where the jumper from frame to engine is on that 'mobile and re-do the connections at both ends to avoid future problems.

author: vk6zgo
author_rank: Super Contributor
timestamp: September 21, 2020, 12:29:07 pm
content: Quote from: Gyro on September 17, 2020, 07:10:13 pmThis is an incredibly stupid idea!My son's VZ Holden Commodore used this method, plus a battery, which if discharged, needed a special high output charger.When it first happened, we stuck my old trickle charger on it, & left it charging for most of a day & night.It started the car, drove OK for a while, then went flat.The bloody alternator never started to charge!He had to take it to a place with the special charger, where they got it going, but it died again, & again!They continued to say both the battery & charging system were OK.Googling, we found hundreds of instances of people having the same problem.The biggest problem was that unlike ordinary batteries & charging systems, you were stuck with taking the thing to an "expert" .I think the primary expertise of these muppets was in fleecing the public!He said goodbye to it in a hurry!Holden had a good reputation for reliability, but the VZ Commodore pretty much destroyed that!Quote

author: HendriXML
author_rank: Super Contributor
timestamp: September 21, 2020, 04:34:50 pm
content: The car has been driven for an hour now. I used a MM and did some reading (after starting) during the drive:Starting: 10,42 VMin: 12,00 VMax: 14,87 VAvg: 12,51 VThe start/stop system did test OK.At entering the car the voltage was: 12,19 VConclusion: the Battery Management System sees the battery as sufficiënt for start/stop. At 12,51V avg the battery does not get charged much I guess.So although the voltages aren't that high the system finds them OK. So I think I just have trust the situation as it is now.For the moment we'll drive the car at least once a week for about een hour. In the mean time I will investigate which solar based charger matches the required specs. The posted example video looks promising.

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 10:07:13 am
content: Quote from: Monkeh on September 19, 2020, 01:18:04 amFor the same reason you aren't supposed to connect the last jumper cable connection to the negative post of the battery when jump-starting a car.... You're supposed to connect to the frame or engine block well away from the battery itself.... It is the official procedure simply to keep any potential sparking away from the hydrogen-producing battery. Obviously, the chances of that actually blowing a battery up in your face are vanishingly small, yet that is the "correct" procedure, none the less....

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 10:12:02 am
content: Quote from: HendriXML on September 21, 2020, 04:34:50 pmThat new battery you have is very low... Did you charge it before putting it in the car?While they are generally shipped in the "charged" state before being filled with sulfuric acid electrolyte at the point of sale, new batteries off-the-shelf are not really, truly at full charge when you get them. You're supposed to charge them up to the tippy-top-top before you actually put them into service.Did you do that?

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 11:10:35 am
content: I've always been an authorized Interstate Batteries dealer, but this excerpt from the typical Yuasa motorcycle battery instructions are more precise:QuoteYuasa makes most of the smaller utility, motorcycle, yard tractor, etc. batteries for Interstate, they're exactly the same except come with green caps and a different label.

author: HendriXML
author_rank: Super Contributor
timestamp: September 22, 2020, 11:17:17 am
content: Most start/stop vehicles contain either EFB or AGM sealed, maintenance free batteries. So no refilling. I did charge it before installing. But it is quite hard to figure out the correct voltages.First fase: constant current charge of 10% C (matches yours) until voltage has climbed up to 14,4VSecond fase keep the voltage at 14,4. Current will slowly drop. Stop when it reaches 1% C.The only thing I'm not entirely sure about wether for an EFB it should have been 14.7 V, just as an AGM.

author: Monkeh
author_rank: Super Contributor
timestamp: September 22, 2020, 12:18:49 pm
content: Quote from: drussell on September 22, 2020, 10:07:13 amSounds well and good but in many vehicles it's not possible to do it that way round. Normally for a battery replacement you'd only ever touch the terminals, which is why I asked.

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 01:16:05 pm
content: Quote from: HendriXML on September 22, 2020, 11:17:17 amEven if you're not the one putting in the electrolyte (which is normal for typical over-the-counter car battery purchases,) I would never trust them to have properly charged the thing initially, let alone somewhat recently after sitting on the shelf... Here they usually at least put those stickers on them saying "should be recharged by...." when they're acid-filled and on the shelf but I trustnone of thatunless I got it directly from my uncle Phil at the warehouse....The procedure is essentially the same for the small AGMs, car batteries are exactly the same idea!!:QuoteThe last small one I personally activated out-of-the-box was a small AGM for the quad that they use at the car wash for snow removal... It took many hours to actually come up to full charge voltage....

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 01:20:20 pm
content: Quote from: Monkeh on September 22, 2020, 12:18:49 pmThen you're doing it wrong!!A proper battery replacement (after actually correctly diagnosing that itisreally the battery itself at fault) in a vehicle should include properly cleaning and re-connecting all inter-related wiring to the actual battery. I know most shops don't do this, but that's why people come to me once they've spent thousands of unnecessary dollars or have been told "that can't be fixed!"

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 01:22:39 pm
content: Quote from: HendriXML on September 22, 2020, 11:17:17 amOn first activation or bringing a horribly-deeply-discharged battery back to life you should hit at least 15.5V for an hour or so... You need to actually charge it all the way up, even slightly overcharge it if you can't measure the actual SG of the cells.

author: HendriXML
author_rank: Super Contributor
timestamp: September 22, 2020, 01:51:28 pm
content: When I received the battery is was at 12.58 VDid some charging, but as said no more than 14.4 V.If I understand correctly you say it might not be activated this way. Will this restore by itself, after a few cycles or do I need to take some action? Like charging it up with the 15.5 V like you mentioned.Btw. What is SG?

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 02:06:54 pm
content: Quote from: HendriXML on September 22, 2020, 01:51:28 pmBySGI mean specific gravity, tested with a hydrometer....And yeah, if you only ever hit 14V it was probably never even totally, fully, equalize charged...If your vehicle actually ever gets to full charge for a while it would essentially do the same thing over time but Ialwayspre-charge to full before putting one in service...which is probably why I typically get 10+ year service life out of my batteries since they're properly utilized and maintained over their entire lifespan....

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 02:10:48 pm
content: The open-circuit voltage of a lead acid battery can beverymisleading.The only true measure is the SG of the individual cells, reading against the correct values for the exact plate chemistry (like how muchCathere is in there, etc.)... follow the manufacturer's datasheet.If they don't supply a datasheet, find another battery supplier!

author: HendriXML
author_rank: Super Contributor
timestamp: September 22, 2020, 02:18:16 pm
content: Its a Varta, getting info on them is a nightmare. The info that came with it is a joke. At their website it says: you shouldn't charge your battery battry yourself. It needs professional care.So that kinda sucks..

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 02:21:47 pm
content: Quote from: HendriXML on September 22, 2020, 02:18:16 pmWhat is the battery model number, I'll see if I can find some proper data...Also, what year is your Focus? I'd like to x-ref it to see what I'd install if it were here...

author: Zeyneb
author_rank: Regular Contributor
timestamp: September 22, 2020, 02:39:52 pm
content: Quote from: HendriXML on September 22, 2020, 02:18:16 pmAnnoying is it! f***ing Nanny state.Now for all dutch members here. I would recommend against accudeal.nl webshop. I bought an Varta car battery from them in this year (2020) and they gave me one from 2017! The people from front line office are the most superficial possible, they can't say anything but No. Only talking to the owner get things eventually done. So eventually I was able to get one from 2020.Also there is a very good video on YouTube where someone explains how you can decipher date codes from the car batteries.Even that owner was eventually willing to admit these instructions where correct.

author: Monkeh
author_rank: Super Contributor
timestamp: September 22, 2020, 02:48:26 pm
content: Quote from: drussell on September 22, 2020, 01:20:20 pmNo. I'm not.A simple battery replacement in an otherwise good condition vehicle does not need to be a two hour long journey into the main fuse box, alternator, starter, potentially multiple grounds.. and where do you draw the line, let alone think disturbing perfectly good connections is wise?And again, I can't do your procedure in some vehicles - my last car had a ground under the battery tray. Good luck with that. Not to mention disconnecting individual grounds from a powered modern vehicle is potentially an extremely bad idea.There's a lot of overthink and unfamiliarity with other implementations going on here..

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 02:59:18 pm
content: Quote from: Zeyneb on September 22, 2020, 02:39:52 pmHence my reasoning for always properly charging any "new" battery you buy....

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 03:03:57 pm
content: Quote from: Monkeh on September 22, 2020, 02:48:26 pmI never said that you normally need to check every possible connection...I was simply stating that if you're sparking the connectionat the battery, that istechnicallythe wrong procedure, whether you are jump-starting or re-connecting a main battery! You'resupposedto do the final connectionphysically away from the batteryto reduce the (already ridiculously low) chance of it blowing up in your face from a hydrogen explosion.

author: HendriXML
author_rank: Super Contributor
timestamp: September 22, 2020, 03:05:43 pm
content: Quote from: Zeyneb on September 22, 2020, 02:39:52 pmI almost bought from them, but saw negative reviews writing the same.

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 03:12:23 pm
content: Quote from: drussell on September 22, 2020, 03:03:57 pmOk, I did kinda say that but that was a bit of hyperbole... Iwouldat least check the main starter wires, etc. and any connections pertaining to the charge coming back from the alternator because often times that is thebloodyobvioussource of non-charge issues and people discarding perfectly serviceable batteries...but it's not a 2h sojourn to check a few connections, FFS, man....Edit:HendriXML's experience is actually a perfect example. His original battery was not likely being charged correctly all the time, and probably would have been perfectly serviceable for more years to come if it weren't for the shoddy ground connection shortening its' life by not charging it correctly. He only noticed the issue much later along the fault-line once it got to the point that it had been abused.I'm quite confident in the way I've used and abused batteries over the years, but..."you doyou"... YMMV, etc....

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 03:25:37 pm
content: Quote from: Monkeh on September 22, 2020, 02:48:26 pmAre yousurethat all of those ground connections are sound?I don't believe the main, most important one onHendriXML's Focus was....

author: Monkeh
author_rank: Super Contributor
timestamp: September 22, 2020, 03:33:50 pm
content: Quote from: drussell on September 22, 2020, 03:03:57 pmI don't disagree that's the correct procedure for jumping. It is, however, difficult to impossible to achieve for replacement in many cases, especially as you really do want to connect and disconnect the entire system at one point. Plus, the risk of hydrogen buildup is massively greater in the case of a charging or defective battery than the connection of a new one.Quote from: drussell on September 22, 2020, 03:12:23 pmYou tell me that when you have engine bays you can't get a hand in. We're not talking about big American trucks with V6 and V8 engines longitudinally mounted in a bay big enough to sleep in, here. Obviously I do visually and where possible mechanically check any reasonably accessible joints, but not all of them are practical. Want to safely get at the starter on two of the cars outside? Intake manifold needs to come off. To get there, you take the battery, battery tray, filter housing, MAF, and throttle body off. Apparently you have to remove the coolant reservoir, dipstick and tube, and wrangle some harness out of the way on the newer one. Not a five minute job,especiallywhen you're not used to taking them apart. Everything is tight, and you need the right tools. Socket a little too thick? Won't get to the manifold bolts. Don't have the right extension? Well, unless you want to remove the radiator, you'll need that one specific length.A few simple tests can easily verify these connections electrically without having to do all this, and there's no reason to disturb the connections if they're sound. Also bear in mind the climate here is less destructive to vehicles.Quote from: drussell on September 22, 2020, 03:25:37 pmThe one which is right there on the strut tower and was only a bad connection after he had to remove it to disconnect the battery?Anyway. The battery sounds like it was properly charged at delivery, but the car isn't charging it as hard as some may expect. Some of these batteries aren't designed to be floated as high as older types. As long as it's given a chance to charge it on a regular basis I would leave well enough alone as long as it's behaving properly after cleaning up that connection.

author: HendriXML
author_rank: Super Contributor
timestamp: September 22, 2020, 03:35:04 pm
content: Quote from: Zeyneb on September 22, 2020, 02:39:52 pmMine was of March 2020, so

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 03:39:10 pm
content: Quote from: Monkeh on September 22, 2020, 03:33:50 pmWith paint underneath, only making actual contact through a couple of threads? (Which isverycommon these days right from the factory?!)Ok, keep thinking that was a valid connection... You should work for Ford or Honda's EE dept.

author: HendriXML
author_rank: Super Contributor
timestamp: September 22, 2020, 03:40:47 pm
content: Does some one know how the Battery Management System gets "synced". Like how and when it has valid knowledge about the State of Charge after a reset. Maybe in my situation it is still learning. (By not charging properly

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 03:53:44 pm
content: Quote from: Monkeh on September 22, 2020, 03:33:50 pmIndeed, however the average Joe is clueless compared to EEVblog forum members....They provide a procedure expressly to cater to the lowest common denominator. You and I can disregard those precautions when we know more about the actual state of things like the condition and charge of the battery in question!QuoteAre you sure? How do you know it was charged, did you put it on your charger with metering?I never said anything about using that battery in float mode, I stated that any reputable manufacturer will instruct the installer to be sure that the cells are fully charged before putting the battery into service. Procedures might vary, but personally, for any chemistry of lead acid batteries that are supposedly "new" off the shelf, I would always bring them all the way up to 15.5-16+ volts for that first charge cycle. You can do whatever you want with your batteries, but I like happy customers (like myself) that don't need to replace their batteries every 3,4,5 years... YMMVI literally pretty muchalwaysget 10+ years out of mine, and we're in a winter climate here in Calgary, AB, and each individual one may sometimes sit for long periods of time, I'm one driver with 5+ 'mobiles... I'm not always nice to "them there cells" but I also know how to bring them back!!Would you like me to go do a date-code video of the ones that are currently in my daily drivers?

author: Monkeh
author_rank: Super Contributor
timestamp: September 22, 2020, 04:03:24 pm
content: Quote from: drussell on September 22, 2020, 03:39:10 pmIf it was working fine, it was working fine. It never caused an issue until disturbed. No doubt it's a crap setup, but the problem was introduced by disturbing it. There's no judgement in that statement, it's not like I've never made a bad connection or stretched a clamp. I've also chased my tail looking for issues which don't exist when the problem was a cheap, 7-year old battery mostly seeing short runs which I didn't want to condemn (mostly because I thought it was a lot newer).Also, I happen to like the two Hondas we have, and I'd rather have them and their 'tiny' single ground straps than the junk America has made for the last, oh, 40 years. Yes sir, your car is out of warranty, so that'll be $700 to fix the wiring harness which failed at three years old because we shaved five cents off by using fewer strands.Quote from: drussell on September 22, 2020, 03:53:44 pmSure? No, it's a reasonable guess from the resting voltage. Not perfect, no, but for a brand new pack the open circuit voltage is a reasonable indication of approximate charge state. Again, serious overthinking going on here without enough knowledge of how the vehicle is supposed to handle the battery.Can we stop debating the relative merits of sealed vs refillable batteries, how far one should go into maintaining things which shouldn't need touching, and how easy it is to work on a car the size of a house, and focus on the reality of, uh, the Focus?Quote from: HendriXML on September 22, 2020, 03:40:47 pmAnd there's the problem with these systems. That stuff might be detailed in their service data, but obviously it's not public. I'm not sure if there are any low-cost services for EU vehicles - in the US you can get fairly cheap access to Alldata, Mitchell, and a number of others for single vehicles, but these services are all pretty US-centric. We need some right to repair action over here..Just go ahead and run it for a while and see how it does, if it gives you any bother I suggest taking it to the dealer (if you trust them, not all are good) or find out if you have a really reputable independent which specialises in this stuff and will know how to handle it.

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 04:06:42 pm
content: Quote from: HendriXML on September 22, 2020, 03:40:47 pmI've never seen one that "learns"....They typically just use a battery temperature sensor and then just add on whatever the immediate operational factors are, like system voltage (normal, historical) and maybe add on rpm or something to skew it, but I wouldn't put it past recent manufacturers to screw with it in other ways... I doubt it, but really I have no idea, YMMV on the really recent "crap" stuff.... Especially if it has stop/start re-crank on red-light... I have no idea how they're trying to "optimize" those batteries but I expect it could be summed up as "poorly"...

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 04:09:17 pm
content: Quote from: Monkeh on September 22, 2020, 04:03:24 pmOk, so you're one ofthoseguys..."If it started yesterday then it must have always been totally perfectly fine...."Nevermind then....

author: IanB
author_rank: Super Contributor
timestamp: September 22, 2020, 04:10:32 pm
content: @drussell, do you have any comments on maintaining the modern type of sealed, "maintenance free" batteries? If you give the battery a long, strong charge up to 15 V or so it will generate a lot of gas, which will deplete the water in the electrolyte. With a regular flooded battery you would just top it back up with distilled water. With a maintenance-free battery, can you do the same? Is there a practical way to open the cell covers and top them up?

author: Monkeh
author_rank: Super Contributor
timestamp: September 22, 2020, 04:10:56 pm
content: Quote from: drussell on September 22, 2020, 04:06:42 pmStop/start systems will typically monitor energy out of and in to the battery so they can recharge correctly and avoid stopping the engine if there's a chance it won't start promptly. All very complicated for very little gain outside of city crawling.Quote from: drussell on September 22, 2020, 04:09:17 pm.. cause and effect. There was no problem until the state of that connection wasactively altered, it's extremely unlikely the problem is unrelated to that fact.

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 04:13:17 pm
content: Quote from: Monkeh on September 22, 2020, 04:03:24 pmReally? I suppose I really should do a battery tutorial video...I have car batteries here that will show you 12.7 volts even after taking the surface charge off with a 30-sec load of a headlamp but won't even hold the 5v to keep the MCU alive on a "toaster tester"....Do youreallyneed to see proof?!

author: Monkeh
author_rank: Super Contributor
timestamp: September 22, 2020, 04:17:22 pm
content: Quote from: drussell on September 22, 2020, 04:13:17 pm... and those are brand new off the shelf batteries which have never been deep discharged or otherwise damaged, are they?Yes, I'm working with the assumption he's got a good condition, brand new battery. It's a reasonable one, stop overthinking this.

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 04:18:43 pm
content: Quote from: Monkeh on September 22, 2020, 04:10:56 pmWhat are you talking about?The OP replaced what would have probably still been a perfectly serviceable battery due to a grounding issue not charging it properly. Sure it was getting older but if it had been treated right it should have still had plenty of life left!I'm out.If any of you would likeproperbattery replacement or other electrical diagnosis in Calgary, AB or anywhere in the valley down there between Christina Lake and Grand Forks, BC, maybe over to Greenwood or Midway, hit me up... otherwise I'm just

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 04:20:54 pm
content: Quote from: Monkeh on September 22, 2020, 04:17:22 pmMy point is that most of the batteries you buy from an auto parts store areNOT IN GOOD CONDITIONas sold!Edit:Authorized Interstate Batteries dealer...

author: IanB
author_rank: Super Contributor
timestamp: September 22, 2020, 04:21:30 pm
content: Quote from: drussell on September 22, 2020, 04:18:43 pmBefore you go, any comments on my question above?

author: Monkeh
author_rank: Super Contributor
timestamp: September 22, 2020, 04:30:12 pm
content: Quote from: drussell on September 22, 2020, 04:20:54 pmAnd I'd like to point out you're coming from a very different country and culture. Yes, there are of course bad shops everywhere but I'm not operating under the assumption he got a bad one off the bat - my experience has been otherwise here.Quote from: drussell on September 22, 2020, 04:18:43 pmAnd where is the proof of this? The battery was deep discharged due to sparse vehicle use over lockdown (see first post). Yes, it may have had a bad ground contributing to that, but the one we've been discussing was bad after it was reconnected - the original state is no longer relevant and cannot be determined. Alotof otherwise good batteries have been knackered in the last six months over here by disuse. Modern cars often have relatively high idle draw and very different charging behaviour to older designs, and they are suffering.Without knowing how the charging system in this vehicle is intended to work, I don't see how either of us can say what may be or was wrong.

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 04:40:11 pm
content: Quote from: Monkeh on September 22, 2020, 04:30:12 pmI didn't say it was "bad", just that I highly doubt it was ever properly charged at activation!!QuoteONEdeep discharge of a battery designed for cranking duty willNOTdestroy it!(If it doesn't freeze or something!)A cranking battery can withstand a hundred or more cycles of deep discharge before the plates physically disintegrate. I use banks of cheap starting batteries all the time in large UPS system duty in the big 24 and 48v configurations because they only ever see a few cycles when the relatively reliable power goes actually out. Regular car "starting" batteries are able to take afewdeep cycles with no problem.You obviously could not use the same ones in repetitive use on an off-grid system!Deep cycle batteries are designed with fewer, thicker plates to take the repetitive abuse from a thousand charge/discharge cycles without enough wear to make things short out, unlike the typical many-thin-plate high-CCA starting battery.Hang on, let me quote Chrysler, I'll go get the '98 Dakota Service Manual...

author: Monkeh
author_rank: Super Contributor
timestamp: September 22, 2020, 04:53:21 pm
content: Quote from: drussell on September 22, 2020, 04:40:11 pm14.4V but not properly floated - stopped at 600mA. So perhaps not fully, but close. Close enough with a conventional alternator, but I do not know how the charging system in this Focus behaves.QuoteBut sitting at that discharge state will. If the oh-so-smart charging system which was never engineered with the thought of a vehicle sitting around for a month or two doesn't charge properly after such an event, the battery will quite rapidly be a lost cause. Sat long enough, there's no hope of recovery (I just replaced one which sat for six months after the owner passed.. probably would survive two, not six).

author: HendriXML
author_rank: Super Contributor
timestamp: September 22, 2020, 05:23:00 pm
content: Quote from: drussell on September 22, 2020, 04:18:43 pmI'll jump in for a moment.Please read the title, I know I didn't took great care of the battery. But instead of bringing it back to life I bought a new one for 125 euros. Thats like 25 euro's per year. With my means to take optimal care for a battery regarding access to the car and a power socket at the same location that kind of money is not be worth the hassle.I don't think at this moment it has or had a charging issue. I didn't drive enough with it for too long and it was getting too old for such suboptimal care.However I'm still charging the old one in batches, and I'm not convinced yet it will return in good state. But I've read that EFB's are quite forgiving about deep discharge so I will continue charging it for some more.The bottomline is doing something suboptimal doesn't necessarily means doing it stupid, there may be practical constraints. (Like access or time)

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 05:41:47 pm
content: For example, the Dak' service manual (3" thick BIBLE) goes into detail about deeply discharged batteries in the Battery chapter, 8A (I'm quoting from pages 8A-13 and 8A-14 from the '98 service manual,) and they are totally correct:QuoteA starting battery is intended to be topped right back up after a brief (but typically high-current) load, and will usually look that way if you data-log it. As soon as you get partially discharged, it won't accept the expected rate of charge nice and quickly like it's supposed to, down all the way to almost drawingnocurrent if it's really low, where it can takedaysto resurrect the cells. They often are actually recoverable though, unless they're physically shorted or something...That doesn't necessarily mean you can't bring them back!You just have to know what you're doing!(and, yeah, sometimes I've brought some back from the dead by prodding them with like 24+ volts... They can even still have very decent capacity left, even though they were deep-dischargedonceortwiceor something....)

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 05:45:45 pm
content: Quote from: HendriXML on September 22, 2020, 05:23:00 pmEven with a few mA constant draw, you should be able to let a car battery sit formonthswithout issue. Yes, they get higher self-discharge as they age, but it should still have most of the capacity left after a matter of covid-weeks...I'd be willing to bet your old one was never being fully recharged, but I've run out of speculative feelings for this thread...

author: HendriXML
author_rank: Super Contributor
timestamp: September 22, 2020, 05:51:25 pm
content: Oh no.. my old battery is acting much better. I could charge it with 6 A right away. (I Think, didn't save the logging of the first batch). At this moment it accepted a total of 48 Ah. But at 42 Ah, the voltage was still below 12 V (11.8 if I remember correctly).

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 05:51:32 pm
content: Quote from: IanB on September 22, 2020, 04:10:32 pmOn the early "maintenance free" ones you could often relatively easily open the cells but many are now totally sealed once they fill them at the factory and then you're SOL.Take great pains to not overcharge them, as that's probably the main cause of failure long-term. If deeply discharged, you still want to blast them a bit but try to limit your duration of gassing and keep it slow. Once or twice in their life a quick run up to 15 won't kill them, but don't leave it on a 1940s selenium-based trickle charger for a day or two like I do with the open-able ones..hahaBasically, just try to never buy one of those garbage-style batteries if you want to actually have reasonable life. They're essentially just absolute junk puffed up with marketing wankery.

author: drussell
author_rank: Super Contributor
timestamp: September 22, 2020, 05:53:55 pm
content: Quote from: HendriXML on September 22, 2020, 05:51:25 pmI pretty much guarantee your "old" battery is just fine, it just needed a good, long, slow proper trickle charge, whichshouldtake several days. Depending on the manufacturer, it might still perform just as well as your new Varta... hahaAlso, remember that on a trickle charge a reasonable chunk of your incoming Ah is going directly to heat, so take that measurement with a grain of salt...

author: HendriXML
author_rank: Super Contributor
timestamp: September 22, 2020, 05:58:24 pm
content: Quote from: drussell on September 22, 2020, 05:45:45 pmIt wasn't recharged at all, don't know wether that means your speculation is right or wrong.I bought a new one because replacing is a hassle. And if the old one could be revived I would have a nice backup, or extra power source for experimenting. Yes I would have loved to recharge the battery in the car, but I couldn't leave my gear unattended and didn't want to buy a charger which would cost half of the battery. Which I then had to babysit as well. For days!!

author: HendriXML
author_rank: Super Contributor
timestamp: September 22, 2020, 06:01:26 pm
content: Quote from: drussell on September 22, 2020, 05:53:55 pmI think the old one performs like an old VartaOriginal Ford = VartaBut that's not a fair statement because we know the new one is not in great shape yet!

author: SilverSolder
author_rank: Super Contributor
timestamp: September 22, 2020, 06:02:25 pm
content: Once a battery has been accidentally discharged to zero a couple of times, I have never been able to get them back up to full performance again - it seems they can be permanently damaged.Mind you, I never tried the 15V - 16V brutal treatment, maybe that does something.

author: HendriXML
author_rank: Super Contributor
timestamp: September 22, 2020, 06:04:15 pm
content: I think mine went as low as 7 V. Not enough to start. But not totally drained I guess.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 22, 2020, 06:15:48 pm
content: Quote from: HendriXML on September 22, 2020, 06:04:15 pmIf it was sitting at that kind of voltage for days and weeks, it may have sulfated the plates badly.

author: HendriXML
author_rank: Super Contributor
timestamp: September 23, 2020, 11:40:22 am
content: Found an interesting document on "smart charging":https://www.motor.com/magazinepdfs/042010_09.pdf/url]I think I'll investigate next which obd2 reader can give some more insight.

author: HendriXML
author_rank: Super Contributor
timestamp: September 23, 2020, 11:53:31 am
content: https://www.focusfanatics.com/threads/smart-charge-low-battery-voltage.776210/page-2This forum also gives an interesting read.

author: Alti
author_rank: Frequent Contributor
timestamp: September 24, 2020, 05:50:06 pm
content: Quote from: drussell on September 22, 2020, 05:45:45 pmOP has a car with battery management.This means that such design has alternator excitation under software control.It can push out 50A at 20V if it wishes to do so. It can even ramp up idle speed if needed.If I were an engineer responsible for designing such a car, I would have cut BOM cost by removing any low power standby electronics and added some lines of code into battery management to compensate for this cheapness. How could a user distinguish 100mA draw + some lines of code, from a low power design that draws 10mA?IMHO you cannot expect low discharge current from a car with battery management. Low power design is more expensive w.r.t BOM and testing, than a bog standard with LDO or zener+resistor. Concluding, if you compare old-fashioned constant voltage charging design and battery management charging design, under same andtypicalusage scenario (lets say 1h drive once a week, minimum) the second design can live with vastly higher standby current because it can copensate that draw in a sustainable manner. Of course covid is not a typical scenario a car is designed for but that is not manufacturer's problem.That is just my hypothesis, based on the assumption car manufacturer maximizes profit.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 24, 2020, 05:57:02 pm
content: Quote from: Alti on September 24, 2020, 05:50:06 pmIt isn't hard to measure the car's total standby current - could be fun if we all had a few minutes to try, and see what is revealed?

author: Alti
author_rank: Frequent Contributor
timestamp: September 24, 2020, 06:14:37 pm
content: Ok, I'll be back in 10 minutes. My car is old-style 20yo with constant voltage charging so this is uncomparable with contemporary cars full of electronics. But still, might be fun to check that.

author: Alti
author_rank: Frequent Contributor
timestamp: September 24, 2020, 06:37:51 pm
content: Standby current is about 12mA, battery capacity is 45Ah, open circuit battery voltage is 12.7V and idling voltage measured on a battery terminals is 14.2V (i think it is constant for whole rpm range). There is no battery management controller in there, just plain excitation controller that feeds constant voltage.

author: HendriXML
author_rank: Super Contributor
timestamp: September 24, 2020, 07:53:26 pm
content: The funny thing is ghat I wanted to measure the standby current when installing the battery. But when connecting the terminal to the body it sparked, and I could hear things switch on. So smart me says to me: that might be more than 10 A. A new fuse would cost like 10 Euro. So I didn't measure the current. After screwing te terminal on, I did try to measure the open circuit voltage right away. But why did my probe spark as well.Smart me had prepared it for measuring currents.. Bye Bye 10 euroI've read that unlocking the Ford gets it into a state in which it draws 4 amps! This might well be the reason my voltages are measuring low. After 40 min it goes to sleep again (a person wrote). I left my MM in the car doing min/max readings and it measured 12.43 V max.Will do the same test again because Before these measurements I had it idling and charge it a bit. Which was only a short time at 14.4V after which it went to 12.8 V or near by.

author: Monkeh
author_rank: Super Contributor
timestamp: September 24, 2020, 07:56:59 pm
content: Yes, measuring current on cars is difficult. Even if you don't crank it there can be some quite high peak draws, it takes some time for things to go to sleep, and with many modern cars just being nearby with the 'key' causes a decent load.

author: HendriXML
author_rank: Super Contributor
timestamp: September 25, 2020, 01:23:34 pm
content: I did a new measurement today, leaving the MM in min, max mode for about48 min (2,88 ks). Because the it is the second time the average is more close to the max value, than the min. My guess would be that the time it enters sleepmode is much shorter than 40 min. A quick calculation estimates about 8 minutes (460 s).I think that's much more likely.Ford Focus calculationsDURATION OF HIGH CURRENTconsumesVoltage measurementsvoltMin :12,100 V ± 5 mVvoltMax :12,350 V ± 5 mVvoltAvg :12,310 V ± 5 mVsecTotalTime :2,88 ks ± 60 sprovidessecHighCurrentDuration :460 s ± 80 s

author: SilverSolder
author_rank: Super Contributor
timestamp: September 25, 2020, 03:11:01 pm
content: Quote from: HendriXML on September 25, 2020, 01:23:34 pmSo, "Volt" means "mA" here right?I measured my Ford Escape, it also has a standby current of about 12mA.That isn't much! - but it is still 2Ah per week... if you add this to the battery's self discharge rate, you can see that you can't just leave the car standing for months and expect a happy ending.

author: Monkeh
author_rank: Super Contributor
timestamp: September 25, 2020, 03:18:39 pm
content: Quote from: SilverSolder on September 25, 2020, 03:11:01 pmCouple that with a charging system which apparently never tops the battery off and isn't even aggressive with replacing the energy used for cranking and you have a recipe for a dead car after a month or two of standing and short drives.Quite happy with my conventional charging system with no stop/start, which also involves batteries which cost half as much..

author: SilverSolder
author_rank: Super Contributor
timestamp: September 25, 2020, 03:25:36 pm
content: I'm now in the habit of connecting a charger to top the batteries off every few weeks, in all the family's vehicles. Time will tell if this will make the batteries last longer (I suspect it might).

author: HendriXML
author_rank: Super Contributor
timestamp: September 25, 2020, 06:44:00 pm
content: Quote from: SilverSolder link=topic=254150.msg3249328#msg3249328No, volts. I don't have a way to measure currents out of circuit yet. Thinking about buying a UNI-T UT210E current clamp though. It is just an estimate calculation that the high current mode of the Ford is not 40 min, but more like 8 min. If it really draws 4 A during that period, just after unlocking the car that would mean a significant loss of 2.7 Ah in 40 min, or 0.53 Ah in 8 min. A big difference. How much it loses after unlocking and in sleep mode, I haven't measured, only read about. Which may not have been a reliable source..Thus using the voltages I could make a estimate of the time it takes for the car to enter sleepmode. Using a stopwatch for 8 min is doable, so I might do that as well. But I felt like calculating it and check it later.Also measuring actual currents in that time seems more useful. Because of the voltage drop I expect there's some serious current draw after unlocking the car (8 min estimate).

author: Monkeh
author_rank: Super Contributor
timestamp: September 25, 2020, 06:47:39 pm
content: Consumption as high as 4A likely only lasts for a few minutes, yes. There will be further stages of sleep for it to wind down through.After unlocking pretty much all the major modules will be woken up and expecting things to happen. It's possible even the radio/nav fires up - get tuned, get a GPS fix, and so forth, even if the display isn't on.

author: drussell
author_rank: Super Contributor
timestamp: September 25, 2020, 07:42:13 pm
content: You can measure the current with the 10A jack on a normal multimeter (I'm lucky for this, my old Amrel is 20A) without blowing the fuse, you just have to connect the battery cable first to get past the capacitor-charging surge, then attach the multimeter andthendisconnect the main connection so the multimeter is left in circuit.

author: tom66
author_rank: Super Contributor
timestamp: September 25, 2020, 09:22:21 pm
content: With my Golf (hybrid) mk7 ignition turned on, with lights and heating/AC off, the car still pulls around 250-300W continuously. I'd love to know what requires that much power in a stationary vehicle.

author: HendriXML
author_rank: Super Contributor
timestamp: September 25, 2020, 09:30:06 pm
content: Quote from: drussell on September 25, 2020, 07:42:13 pmI've still a MM of 25 years ago, a Dynatec or something. It has an unfused 20 A mode as wellShould check it's accuracy in that range.Using a bench MM with logging would also be an option. Just with some "shunt wire" and sensitive voltage mode.But for the moment the car will get at least one hour drive a week and I would like to know wether that's enough. Soo not too much experimenting/resetting stuff. The question is when will it do some serious charging.I also have to take the following into account: the first time the old battery was flat. The car took a jump start. Which was -looking backwards- not entirely done correctly. The jump cables where probably removed too soon. One other thing I noticed is that the radio still works but that it doesn't play from the usb-drive anymore. (Disk seem ok under Windows) It may be unrelated or because of some reset, but who knows. The car did charge after the jumpstart (started on the way back). But it was flat again, the next (I think) ride some weeks later.Yeh I know I should have figured out that it needed a lot more charge to be healthy again.

author: HendriXML
author_rank: Super Contributor
timestamp: September 25, 2020, 09:36:19 pm
content: Quote from: tom66 on September 25, 2020, 09:22:21 pmThat's a lot. Maybe to heat something up?

author: SilverSolder
author_rank: Super Contributor
timestamp: September 25, 2020, 10:51:30 pm
content: Quote from: HendriXML on September 25, 2020, 06:44:00 pmI used a UNI-T UT210E to measure my car, funnily enough. It is an awesome little meter.I have made a calibrated piece of wood that holds the clamp open a specific amount, so it gets a new 200A range for measuring starter motor current!

author: drussell
author_rank: Super Contributor
timestamp: September 26, 2020, 03:10:26 am
content: Quote from: tom66 on September 25, 2020, 09:22:21 pmGeez, you should see a Mercedes... Especially those like an SL50 or SL63 with the retarded "let's do everything with fiber optic connections" setup. Had to repair the audio amplifier that wasn't working to make the bus that was never going into "quiet" mode and keeping the whole vehicle bus online, discharging a fully charged battery at 5+ amps 24/7.If any one device doesn't provide the expected result, you keep the whole damn bus alive?! What a farce...When I turn off the ignition key on my van, there are 0.0000 mA flowing.It is completely disconnected. Andthat'sconvenient!And it's not evenpoints! It's just pre-computer!

author: SilverSolder
author_rank: Super Contributor
timestamp: September 26, 2020, 02:15:24 pm
content: Just checked a mid noughties Mustang, it draws zero mA when the ignition is off - despite having computers. Looks like the good engineers at Ford are working on the Mustangs, LOL!

author: drussell
author_rank: Super Contributor
timestamp: September 26, 2020, 02:34:45 pm
content: Quote from: SilverSolder on September 26, 2020, 02:15:24 pmThat's weird, usually you can measure at least a mA or two for the clock in the radio, even on older vehicles without a computer at all. On the van, the two decks are connected to the auxiliary deep-cycle battery & secondary alternator. The main starting battery has nothing connected at all that draws juice with the key off.Are you using the 10A jack, maybe your meter isn't picking up the few mA at the very, very bottom of the high range? I've always been impressed by the ability of my Amrel to measure even single mA loads on the 20A range. I basically never need to even use the mA jack.The thing is 30 years old, even has a yellow holster from the days before Fluke went ballistic on the cloners or anyone at all who dared to use a yellow holster. I wish they still made multimeters.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 26, 2020, 03:02:06 pm
content: Quote from: drussell on September 26, 2020, 02:34:45 pmI am using the Uni-T clamp meter (UT210E), it is good for pretty low currents. It detected 12mA on the Escape, for example. That said, it could very well be that the Mustang drew e.g. one mA or two, which this meter might not be able to see. - I will test the meter on a constant current source later today, I'm curious now!

author: drussell
author_rank: Super Contributor
timestamp: September 26, 2020, 03:09:48 pm
content: Quote from: SilverSolder on September 26, 2020, 03:02:06 pmI didn't realize you were using a clamp meter. Indeed, that should be interesting. I don't trust a clamp meter for very low currents or extreme accuracy, though it's probably actually half decent if it can zero itself properly, the clamp actually closes completely, etc.If you can get enough wire length, you can also loop it through the clamp multiple times and then divide the reading by the number of turns through the clamp to help with very low readings.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 26, 2020, 06:12:11 pm
content: Quote from: drussell on September 26, 2020, 03:09:48 pmOK I tested it, 10mA is about as low as this clamp gauge can be used even as an indication, and that is with tongue at the right angle etc. as the Earth's magnetic field and any ferrous metal nearby begins to have a big effect - it is almost impossible to "hold" a perfect zero. It won't "see" 1mA. Next time, I'll use an old school ammeter or a shunt... or, as you suggested, wrap a piece of wire several times around the clamp. That might be the safest way...

author: floobydust
author_rank: Super Contributor
timestamp: September 28, 2020, 03:25:06 am
content: A modern ECU does some housekeeping when the IGN key is off. Such as run the fuel pump to cool off the fuel rail and prevent percolation, if the engine is hot. It will do an evaporative emissions (EVAP) leak-detection test, so run the LDP pump and toggle some solenoids. The ECUI will test the throttle position motor and sensors. It's just weird to hear a parked car do this. Expect mysterious jumps in current drain on a parked vehicle. The BCM can stay fully powered up for a few minutes after key-off, and even then it is always listening for keyfob remote signals and TPMS signals.Subaru are notorious for their ECU's drawing 75mA quiescent, owners finding the battery goes dead quickly if the car is parked for over a week, and that the battery is lucky to have a 3 year life. An ECU firmware update fixed this somewhat but they would not offer any battery warranty coverage.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: September 28, 2020, 03:45:05 am
content: Modern ECUs do do a lot of stuff, which makes finding problems even more difficult. My aforementioned problem vehicle has three siblings of the same year and model which can be parked for days to weeks without problems. Their housekeeping chores are done fairly quickly after shutdown and current drops to a level comparable to self discharge. The problem vehicle behaves similarly after shutdown, and apparently one or more systems wakes up again sometime later. I only caught it in the act once and it went away again before I could localize the problem.Sorry to hear that Suburu has a more systematic problem.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 28, 2020, 01:26:34 pm
content: Interestingly, a lead-acid battery has LESS self discharge when it is cold... so the problem shouldn't be any worse during winter, it might even be better!

author: HendriXML
author_rank: Super Contributor
timestamp: September 28, 2020, 01:59:21 pm
content: A little update on how the battery fares.We still drive only once a week, 2x 30 min.The day after the ride of previous week the "unlock" voltage was 12,20 V.Today this voltage was 12,07 VIt's not sure what the load is at that moment.The first 30 min of driving the average "charging voltage" is 13,66 V, the way back 12,60 VStart/stop did work, an indication the system sees a healthy battery. Also the system seems not eager to charge the battery much.I think this weekly cycle can be sustained with no issue.From this I can conclude that if there were a problem, at the least the system would be faulty for not charging enough. (But it certainly does charge).

author: floobydust
author_rank: Super Contributor
timestamp: September 28, 2020, 08:20:21 pm
content: Quote from: SilverSolder on September 28, 2020, 01:26:34 pmI couldn't make sense of that "paper", they guy is all over the place with generalities about self-discharge. His numbers are also out to lunch:"New batteries with lead-antimony grids lose about 1% of charge per day at 25°C, but the charge loss increases by a factor of 2 to 5 as the battery ages. Batteries with non-antimonial or high Ca content grids lose less than 0.5% of charge per day REGARDLESS of age."I use manufacturer specs of -3%/month for AGM and -5%/month for flooded battery self-discharge. Someone is out by a factor of 10.

author: floobydust
author_rank: Super Contributor
timestamp: September 28, 2020, 08:25:05 pm
content: Quote from: HendriXML on September 28, 2020, 01:59:21 pmI did a chart comparing state-of-charge vs voltage numbers given by a few lead-acid battery manufacturers.12.07V is quite low for resting voltage SOC ~50%, and 12.60V is not charging at all on the way back. Seems strange.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 28, 2020, 09:23:13 pm
content: Quote from: floobydust on September 28, 2020, 08:20:21 pmIf we go with his statement of "less than 0.5% loss per day", it works out to "less than 14% loss per month (30 days)" - Temperature not stated.If we go with the battery distributor's figure of "4% per week", it works out to about 15% loss per month (4 weeks) - at 80F (~27C).Or, take the battery distributor's figure of "3% per month" - at 65F (~18C) - which pretty much agrees with your figure.It seems to me that all of the quoted numbers, including yours, might be correct - they are just taken at different temperatures?

author: HendriXML
author_rank: Super Contributor
timestamp: September 28, 2020, 09:58:00 pm
content: Quote from: floobydust on September 28, 2020, 08:25:05 pmNice graph! I think an EFB is comparable to a AGM.As I found out the "unlock voltage", the voltage one measures after unlocking to get access to the port is not the resting voltage, as significant current is been drawn. After a while (10 min) the car will go to sleep and the voltage rises around 250 mV.Also I've read the Focus keeps the battery somewhere above 80% SoC. Tomorrow I'll do some measurements which tells what the unlock/rest voltage is after the ride of today. It could well be the car is still "tuning".How does it determine the SoC? Some reading says it needs the resting voltage (8 hr after locking). But whether that's the only thing?For EFB batteries there's a CC -> CV way of charging, if it would follow that it could get into a known state as well.And because I charged it myself this way to >95%, maybe the losses of one week are refilled easily.I've also read that a battery needs some cycles to get to it's optimal performance.This all makes it hard too determine wether something is even wrong.Yes the voltages seem low, but the most important voltage is the one at which it drops when starting the car. That one is around 10.4 V. That's probably not bad, however it is only a small 1.0 L engine..Running full diagnostics in this fase seems not justified yet.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 28, 2020, 10:12:56 pm
content: Here's a graph from Battery University that shows how long a battery can be left without recharging - Notice how temperature dependent this is. If it is hot out, it will self discharge very fast.Who knew!https://batteryuniversity.com/learn/article/elevating_self_discharge

author: floobydust
author_rank: Super Contributor
timestamp: September 28, 2020, 11:34:16 pm
content: At low temperatures, there's less self-discharge but also less capacity by the same amount so I don't see any gain. ref.Power-Sonic Sealed Lead Acid Batteries Technical ManualMy math 50Ah car battery at 5%/month self-discharge corresponds to a 3.5mA load or 2.5Ah/mo lost.The Focus would have to know the battery current to do precise battery management. They might just estimate battery current if the loads are known. What's that hyper-engineering good for? It will certainly stump average mechanics into selling new alternators for no reason, and I find Coulomb counters do not work very good. They just aren't accurate enough as batteries waste a lot of energy (need extra charging) particularly with cold weather and age.I have to make a car battery float charger, I did buy a cheap one but it will surely blow up soon, capacitors run really hot. People are using Battery Tenders and I have to wire up a waterproof connector/cable through the front grill so I can charge it without opening the hood every time.

author: HendriXML
author_rank: Super Contributor
timestamp: September 28, 2020, 11:54:00 pm
content: I found this document explaining smart charging.https://mega.nz/#!VoRDUDJD!91ysT60dpehZ7K2QFacFty4QKIpss9g036qKd0JPoE8

author: HendriXML
author_rank: Super Contributor
timestamp: September 29, 2020, 12:52:12 am
content: Quote from: floobydust on September 28, 2020, 11:34:16 pmThe Focus has a battery monitor sensor (hall effect I believe) to do the accounting.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 29, 2020, 03:31:38 am
content: Quote from: HendriXML on September 28, 2020, 11:54:00 pmVery interesting. I think I "get" it now. Ford is using the generator as a kind of brake... so when you are slowing the car down, the alternator is generating extra power during the braking, and capturing waste energy and using it to charge the battery! That's why it has to be kept down to 80%, so there is "room" for the braking energy to fill the last 20%. Basically, it is a super cheap "hybrid" using a lead acid battery...That is actually very clever...

author: tom66
author_rank: Super Contributor
timestamp: September 29, 2020, 06:07:43 pm
content: Quote from: SilverSolder on September 29, 2020, 03:31:38 amBMW has had this for a while, it is called EfficientDynamics. It's really not much power at all, around 1kW regen. Given 30kW regen on my car just feels like lightly tapping the brakes in a regular car, I have my doubts about how much energy this feasibly recovers, but I suppose it is better than not doing it, and provided the battery is modestly sized and the electrical system can cope with the voltage fluctuations, it's probably just a software problem so it's a free fuel economy boost on city-drive stop-start routes.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 29, 2020, 06:14:25 pm
content: This system can probably kick in even when you just let off the gas during normal driving, given how little energy it siphons off... I agree that we cannot possibly be talking big numbers in terms of efficiency gains, but that's what getting efficiency is often like in the physical world - honing it, percent by percent, until you overall get a pretty good result. Think sailboat, or glider, or something like that. Never ending optimisation!

author: HendriXML
author_rank: Super Contributor
timestamp: September 29, 2020, 07:30:09 pm
content: I just had to calculate the kinetic energiy in Ah of a Focus at 80 km/h.FORD FOCUS KINETIC ENERGYconsumesFord Focus specificationskgWeight :1,316·10³ kgBattery specificationsvoltNominalVoltage :12,6 VintermediatekmhSpeed :80 km/hmsSpeed :22,2 m/sjouleKineticEnergy :325 kJprovidesahKineticEnergy :7,2 A·hThat is significant, but off course it cannot handle that kind of energy in seconds. Also for true regenerative breaking AWG batteries seem to be required.If one releases the gas often, during longer periods (descending hills for example), it might perform at its best on a Focus like ours.

author: HendriXML
author_rank: Super Contributor
timestamp: September 29, 2020, 07:45:12 pm
content: To day I measured the voltage after the weekly charging of yesterdays ride. It was 12.40 V so looking at the graph floobydust posted, thats very near 80% SoC.So driving 2 x 30 min a week is more than enough. It could do its charging alse in 1 x 30 min.I've read that from time to time the system will charge the battery with more juice to keep it healthy.Why did the old battery die on us? It is probably a combination of:Hot weather (>35 deg, much hotter under the hood)Corona (not going on holiday with car)Age of batteryNo casual driving for some time

author: SilverSolder
author_rank: Super Contributor
timestamp: September 29, 2020, 09:18:01 pm
content: It is all starting to make sense. Modern cars are so crazy complicated!

author: tom66
author_rank: Super Contributor
timestamp: September 29, 2020, 09:40:35 pm
content: I worked out roughly that coming from 70 mph to a red light on part of my commute nets me around 100Wh. Or about ~0.3 rated mile in my vehicle.More significant is any constant downhill slopes where the car can use nearly zero or regenerate a slight amount of energy - there's one where I was generally travelling about 35 mph in traffic down hill which seems to be the optimal point for energy recovery as drag is fairly minimal. Total regen is around 20% over the drive, so look at it as adding about 20% more range than you would otherwise have, I suppose. The data below is from a commute between Halifax, UK and Morley, UK, about 12 miles and using a total of 4.4kWh, the cabin heater turned on as outside temperature was around 8C. (I no longer live or work here so I'm comfortable sharing this data.)One nice thing about my particular car - others may have this feature too - is that while 'regen'ing down a hill you can press the accelerator pedal to reduce the amount of regen, without actually accelerating the vehicle. This allows you to carefully modulate the acceleration of the vehicle while recuperating the most energy. The adaptive cruise control does this too; though disappointingly I recently drove an MG ZS EV which, I noticed, during ACC operation never used regen at all. It simply applied the physical brakes, and coasted the electric motor. Wasting energy through poor software design!I consider this commute to be reasonably representative of a commuter town to suburb journey; speeds vary considerably throughout (from 30mph town, through 50-60 mph rural, to 70mph motorway), there are opportunities for regen but also acceleration is required to keep up with traffic and for traffic lights etc. So if a vehicle which can regen up to 45kW can only recover around 1kWh out of 4.4kWh of motive energy, I suggest that one that can recover around 1kW, is not likely to get -that- much benefit. This is perhaps why I'm quite skeptical of mild hybrids, which often feature <400Wh packs and are capable of only a few kW regen which require the engine to be turning anyway (no engine clutch unlike a true hybrid).

author: HendriXML
author_rank: Super Contributor
timestamp: September 29, 2020, 11:02:16 pm
content: Nice info!Quote from: tom66 on September 29, 2020, 09:40:35 pmIn your vehicle a lot of energy seems to be harvested then.In ours it would probably not even be a %. I once noticed however (in an older Mondeo, I think) that while breaking the climate control air became cooler. I think the airco clutch is engaged when a cold buffer would be beneficial. Maybe that might result in better savings in a non hybrid car.

author: tom66
author_rank: Super Contributor
timestamp: September 30, 2020, 09:59:10 am
content: One thing that would be interesting to investigate, for winter drives at least, when regen is generally limited on many EVs (cold Li-Ion packs cannot absorb much charging energy) would be to dump 10kW+ into a resistive heater to warm up the cabin heating loop. Excess heat could be dumped out via the radiator as required. A friend of mine has a Model S and below 5C he reports regen is essentially disabled with anything more than 80% SoC, progressively becoming available as the pack discharges. Some way to make use of that regen energy that is available would be nice.Regen is of course only preferable if you *had* to brake (or can maintain speed within legal limits while recuperating e.g. down a hill); in all cases it is more efficient to coast if that is possible. My car will switch the engine off when doing 70 mph down a gentle slope, as the electric motor only needs to put out a few kW to maintain speed and the engine has poor thermal efficiency at this operating point so it's better to use some battery energy here. It then replaces that battery energy when the engine is next under higher load. While this sounds a bit like "robbing Peter to pay Paul", it seems that engines do better when heavily loaded.When I had a pure ICE car (incidentally a Focus, though 2008 model so I think Mk2) I practiced with a few fuel economy tricks. On hills I would gun it, accelerating to the speed limit quickly putting the engine under good load. Then, as I came over the crest of the hill, I would coast down as much as possible, with the car in a high gear. In stop-start traffic on a slope, I'd switch the engine off and use the handbrake to control progress. I've no data for whether this improved consumption much unfortunately, but I think it's notable that my hybrid does some of the same things now automatically.

author: tom66
author_rank: Super Contributor
timestamp: September 30, 2020, 10:34:50 am
content: So I got myself wondering what effect the total regen power availability has on efficiency. And the answer is perhaps unsurprisingly, that a 1kW regen is not that effective, although it has a much greater effect than I expected. Using the same data set as before I calculated that a 2kW regen would recover 220Wh over the 12 mile drive, or about 18Wh/mile. Given a typical vehicle electrical system consumption of 300W (including DRLs, cabin fan, computers, ABS, radio etc.) over the 30 minute drive this would recover virtually all the electrical system energy, meaning the car could operate with the alternator in coast most of the time. Of course, the battery has to support the vehicle systems for some time without regen, but it has a better effect than I expected.I suppose this is probably one of the cheapest improvements that can be made, especially as many modern cars have stop-start engines already and the NEDC and WLTP tests both include deceleration periods. However, the data makes pretty clear that you really want to have at least 15-20kW regen to start recovering a substantial amount of the energy available. Perhaps it is of no surprise that the Prius (with its 1.5kWh battery) limits regen to around 30kW. My car maxes out at around 45kW although the full regen is only mapped when the brake pedal is depressed - it is normally only ~30kW with accelerator released, so it is possible that a higher regeneration limit would be more useful. (For instance, the Porsche Taycan EV has a regen limit of over 250kW!) However it surprised me how early this curve tails off.

author: HendriXML
author_rank: Super Contributor
timestamp: September 30, 2020, 11:21:45 am
content: Quote from: tom66 on September 30, 2020, 09:59:10 amA side note from what I know:When slowing down on our Ford if one keeps the clutch enabled, no fuel is injected. If one disables the clutch, fuel is needed to keep the engine running. It is not a good idea to let the engine which is off, run with an enabled clutch. But I think that would also result in lousy drive experience..There's an internal optimal rmp/torque in respect to efficiency. So every individual hill would have it's optimal combination. But a good rule of thumb can probably be found experimentally, or using some curve on the internet.But for a combined internal and external optimum, rolling resistance and drag resistance should also be taken into account. Youtube channel Engineering Explained has probably some related vids on that.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 30, 2020, 01:41:58 pm
content: Quote from: tom66 on September 30, 2020, 09:59:10 amThis is correct, it is called the "Specific Fuel Consumption". It turns out that an ICE is most efficient at about 2/3 open throttle (give or take, depends on engine)."I was trying to maximize fuel economy, Officer!"

author: tom66
author_rank: Super Contributor
timestamp: September 30, 2020, 06:14:02 pm
content: My 2005 Peugeot 206 (diesel) would also shut fuel injectors off when coasting, you could see this on an oscilloscope. Seems pretty common on any modern fuel-injected computer controlled car.The really good hybrids, like the Priuses, use a complex electronic dual motor (Toyota calls it "e-CVT" or "Hybrid Synergy Drive") arrangement which is much more fuel efficient than the single hybrid motor in my vehicle - principally because it allows the engine to operate at a variable ratio to the wheel speed rather than using the limited ratios available through a multi-speed gearbox. So the engine can be kept in that nice rpm/torque range, with optimal fuel efficiency, while propelling the vehicle at almost any speed - the engine RPM will only change as required to maintain acceleration requirements or under high load (steep hills, flat hybrid battery, cold start etc)Still - you really can only get the best economy by using pure electric drive as even the best ICE diesel achieves about 35% combined thermal efficiency compared to the 85-95% of an electric drivetrain.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 30, 2020, 06:37:40 pm
content: Another thing a hybrid system could do, is keep the engine under higher load to keep the specific fuel consumption down. The generator and battery would have to be able to take the output of the ICE at 2/3 throttle - but we are very far away from being able to do that!Supercapacitors, maybe? Would also require a much larger generator, one that could deliver 60% of the ICE power output - maybe something like a 50KW generator would be needed!This way, you would run the ICE only once every e.g. ten minutes, at high power, then shut it down again - and live off the electricity generated during the short sprint of power...

author: tom66
author_rank: Super Contributor
timestamp: September 30, 2020, 08:28:54 pm
content: I really need to dig out my data capture dongle again and get some data, but that's *kinda* how my Golf hybrid behaves.I notice on the instantaneous consumption gauge that on a short cycle - about every 30 seconds or so - the car alternates between loading the engine fairly heavily, to charge the battery up, and then puts energy out to the wheels via the electric motor. It doesn't shut the engine down completely if load is needed from the engine.I think the problem with shutting the engine down is the engine, the oil, and the exhaust system all begin to cool, which impacts upon efficiency and emissions.It surprises me that this is more efficient than just using the ICE to directly drive the wheels, but I suspect it's one of these very minor tweaks, that gets it a little bit further.I also notice that if I get into the car when it is cold it will draw around 1.5kW from the engine to put directly into the coolant heater - regardless of whether you have cabin heat enabled - this appears to be there to warm up the coolant loop more quickly. Double bubble as the extra load will also warm the engine up quicker. It doesn't apply the full 4-5kW of load on the engine that it can use as a generator, until the engine is warmed up completely. There's definitely some smarts in the combined engine/hybrid control unit.

author: SilverSolder
author_rank: Super Contributor
timestamp: October 01, 2020, 02:06:06 pm
content: If you look at this graph, as a kind of example of what the curve of specific fuel consumption can look like when plotted against engine load, you will see why your hybrid car does what it does... even loading the engine slightly brings a big economy improvement. Obviously the max economy is much further along, but currently unreachable!

author: tom66
author_rank: Super Contributor
timestamp: October 01, 2020, 05:16:55 pm
content: In terms of regen/charge rate, while my car is limited to around 4.5-5kW from the engine in normal use, a friend has the later model GTE which can regen charge at around 20kW continuously, for at least 30 minutes, which is sufficient to recharge the battery completely.

author: SilverSolder
author_rank: Super Contributor
timestamp: October 01, 2020, 06:44:02 pm
content: That graph also explains why a small engine gets better fuel economy than a large one - the smaller one has to work harder, and is therefore intrinsically more efficient!I work around that by using a large engine and keeping the speed up!

author: tom66
author_rank: Super Contributor
timestamp: October 01, 2020, 08:53:01 pm
content: Yes, I'd really like to see a PHEV with a 0.9L 3cyl engine, connected to a 20kWh battery and 200hp electric motor. It would get good fuel economy but allow most people (at least in Europe) to electrify short journeys. But with the cost of batteries falling adding an ICE hardly makes sense any more hence why the PHEV is a dying breed.

author: SilverSolder
author_rank: Super Contributor
timestamp: October 01, 2020, 09:19:39 pm
content: Quote from: tom66 on October 01, 2020, 08:53:01 pmEven if charging stations were everywhere, PHEV still beats EV in terms of fast "recharge" - making it good for long journeys, or even heavy use in city traffic (taxi or delivery vehicles that can't afford long downtimes, for example). There is also the issue of living in an area with occasional power outages lasting long enough to become a problem for an EV. Basically, it seems to me a PHEV is an animal with a lot more survival skills than a pure EV!

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 01, 2020, 10:40:11 pm
content: An easy trick to boost MPG is "pulse and glide" that involves alternating between running the engine at its peak efficiency point and coasting, the goal being to control the average speed. That works especially well on hills.

author: HendriXML
author_rank: Super Contributor
timestamp: October 02, 2020, 07:53:40 pm
content: Quote from: SilverSolder on October 01, 2020, 06:44:02 pmEcoboost engine of our FoFo is 1 L, 3 cylinder. So everything is lighter (pistons have alternating directions, I think that results to losses), and have less area and probably less friction. Using a turbo keeps the energy density comparable. (They don't need more rpm).Being lighter and having a way to change the energy density (more or less turbo) will probably result in a more spread out and flatter efficiency curve.But if one starts calculating global efficiency, drag will become dominant in reducing efficiency at higher speeds. So the sweet-spot of efficiency will be mostly determined by front surface x coefficient of drag, not the sweet-spot of the engine.