BMW in-car computer battery stats - Page 1
Forum section: electronics / general

author: Rick Law
author_rank: Super Contributor
timestamp: May 10, 2014, 06:30:42 pm
content: Hi, anyone familiar what the 1997 BMW328i's in-car computer do for battery charging?I know that for sure later year cars charge based on accumulated battery stats (in their car manual). The stats need to be cleared with new battery or it will not charge right, or not charge at all, or kills the battery out right by improper charging.I think the 1997 do that too, but I am not sure (certainly not in my car manual). I once put in a new Diehard at Sears and it died in the first month (matching some of the symptoms described when stat is not cleared) --- BUT I don't remember what the BMW mechanic at the dealer told me anymore - only recalled that dealer said he wont touch it unless I agree to remove the 3rd party battery...Other web search returns conflicting results.ThanksRick

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 10, 2014, 11:35:43 pm
content: One possible workaround is to put in a deep cycle (marine) battery along with a plug in charger to top it off with.

author: VK5RC
author_rank: Unknown
timestamp: May 11, 2014, 04:57:21 am
content: I thought a deep cycle battery wouldn't have the ability to give you the very large currents to start a car, different plate structure (thicker but lower surface area), in my country batteries are typically changed by the local motoring roadside assistance organisation, over the last few years I have not had one problem and the software hasn't been changed /updated. The guys kept 12v up to the computer during the actual removal of the battery but nothing else. I have had no comments from the OEM at formal service work from Mercedes or Volvo. I have heard that you do get dud batteries and that modern cars esp the 'eco" ones are really tough on batteries.

author: Thomas
author_rank: Regular Contributor
timestamp: May 11, 2014, 10:53:13 am
content: I have a 2002 520i, and it does not have battery stats. I think that came in 2005, but I am not 100% sure. Might be different between series too.My alternator just died a few weeks ago, and the car didn't warn me in any way. This leads me to believe it just has a "dumb" voltage regulator and no real monitoring. Surely it would have detected the voltage at ~11.5V and warned me?I just replaced the alternator, all fine now.Are you sure your charging is working properly?I measured the voltage on the post in the engine compartment. It is ~12.5V with engine not running, rising slowly to ~14.5V a few seconds after starting it.You should have at least 13.8V with engine running.

author: Rick Law
author_rank: Super Contributor
timestamp: May 11, 2014, 03:33:08 pm
content: Quote from: Thomas on May 11, 2014, 10:53:13 amThanks for the reply, Thomas.I just starting the debugging, but I am fairly sure it is the battery. Possibly one dead cell since after attempted start, I saw a brief moment when the battery dropped to 10.x Volt (it was in the rain and I was not sure what I saw however).I am sure the alternator is working (14.x volt while driving.) I am not sure about if the battery gets charged since I didn't test at the trunk-end but instead just measure the V at the cigarette lighter part. I will try to test more later when I can open up the trunk/hood without getting everything wet.This is a 6 to 7 year old battery, so it has done its job. The independent mechanics seem to have died off. I know a battery replacement is going to be $600+ at the dealer.VK5RC, thanks for the suggestion - interesting one. But I think marine battery likely will not give enough amps to start the car. My alternative really is to get a cheap battery and hope for the best, or bite the bullet and get one last battery from the dealer for this car...Thanks both.Rick

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 11, 2014, 04:00:19 pm
content: Quote from: VK5RC on May 11, 2014, 04:57:21 amThere's a difference between marine deep cycle and stationary (off grid) deep cycle. The former is designed for starting engines, with a trade off that it doesn't handle deep cycle as good as the stationary type. Basically it's just a car battery with a modified design to better withstand deep cycling.BTW, in many newer cars (and a few older ones as well), the battery is in fact a deep cycle type in order to allow the alternator to be switched off under heavy engine load and on during braking in order to improve efficiency. That could explain why a regular starting battery doesn't last long.

author: dannyf
author_rank: Super Contributor
timestamp: May 11, 2014, 04:02:25 pm
content: QuoteBMW replaced a battery in a 2009/2010 X3M for me, under warranty. The battery would have cost me $380 + labor. The dealer said that it had a chip in it so an off-brand battery wouldn't work.I have replaced a BMW battery in a 2004 330i with one bought at Walmart. No problem whatsoever.I think the chip'd batteries are a recent phenomenon.If the electronics wouldn't charge up a fully depleted battery, you may want to pre-charge them. Battery chargers are fairly inexpensive now.

author: SeanB
author_rank: Super Contributor
timestamp: May 11, 2014, 04:10:02 pm
content: It is likely the battery is dead or dying. When you are in the trunk looking at it pop the top cover off and open the cells, it is likely that it is low on water. When you do pull it out check as well that there is no corrosion on the connectors and the cables, and that the connection to the body is good as well. I have had a few batteries die suddenly, generally just out of the warranty period. My one decided to crack a plate on a Saturday at 12, just as I wanted to go out. A quick 20 minute charge and a drive to Midas( only place open) and $100 later I got a new one, and placed it in the car when I got back. Parked on a hill so I could bump start the car. It would self discharge one cell to useless in about an hour, so I got 2 start cycles out of it in quick order before replacing the battery. Then the hunt for the booklet with the radio code. Enter 4 digits then press right arrow and radio works again, after the 1 hour wait.BMW now has a battery with DRM? There are laws against that in some countries.

author: zapta
author_rank: Super Contributor
timestamp: May 11, 2014, 04:13:50 pm
content: Quote from: Rick Law on May 10, 2014, 06:30:42 pmThat's strange before you can charge/discharge the battery without the car's knowledge (e.g. connecting a battery maintainer directly to the battery or connecting a load).

author: Rick Law
author_rank: Super Contributor
timestamp: May 11, 2014, 10:26:15 pm
content: Quote from: dannyf on May 11, 2014, 04:02:25 pmWhat caused my concern was the last battery change 6 or 7 years back, Sears put in a new Diehard that acted funny and died within a month. The dealer ended up replacing the one month old battery with BMW battery to make the car run. (They wont look at the other problems until it was replaced...) It was too long ago, I forgot what the problem was and what he said about that battery.Well - I think I will do some poking around tomorrow (if it doesn't look like it will rain like it does today), likely get a walmart battery and see if the darn thing works...As Zapta said also ...you can charge/discharge the battery without the car's knowledge (e.g. connecting a battery maintainer directly to the battery or connecting a load)...Thanks for the input, guys...

author: Rick Law
author_rank: Super Contributor
timestamp: May 20, 2014, 09:11:31 pm
content: Well, found an independent mechanics to "register the new battery with the in-car computer" for $35.I installed the new (non-BMW) battery a few days back. I do notice that on my drive home from the mechanics, voltage is running more like it was a couple of years ago. (Cigarette lighter plug voltmeter,+-2% accuracy).Of course, the voltage alone doesn't tell me the SOC. It did seem to think the battery is full a lot more before this "battery registration" and it thinks it needs charging more on the way back - which fits my expectation. When the battery was first installed, it thinks the battery is full in less than two minutes. I did not believe it would have been full that fast given it must have been sitting at the store for weeks or months. So, its "charging more on the way home than on the way there" is what I expected to see (or what I made myself think I saw... hard to say).Whether I may be merely seeing what I expected...anyhow...fingers crossed, hope the guy did it right and this will last a few years...

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: May 21, 2014, 12:42:04 am
content: Here is how to video for 2009 135i:http://www.carcarekiosk.com/video/2009_BMW_135i_3.0L_6_Cyl._Turbo_Coupe/battery/replace_battery.Judging from same problems with Laptop batteries - "chip" needs to know a history of particular battery in order to estimate its performance. Without reset it will use historical data from old battery to estimate how much charge left. Charging circuit should not kill the battery unless it uses completely different technology or it was designed by an idiot - try to find new "registered" battery in the middle of Mongolia.I had older Audi A4 pretty much completely hacked back in 2005 using $200 programmer that I purchased from someone online. I am sure there are instructions and codes in internet somewhere you just need an ODB2 to USB/Bluetooth adapter. There are open source software that allow you to look at warning codes etc. - opendiag or freediag, or commercial programs - around $200.Dealer-level bi-directional programming tool can cost you about $1500 and you have to pay for updates - so no wonder they charge $30 for reset.$400 programmer may worth it if you plan to work on your car yourself regularly. I have heard that LAUNCH X.431 is pretty good for BMW but never used it myself.

author: Rick Law
author_rank: Super Contributor
timestamp: May 21, 2014, 01:17:02 am
content: Quote from: Alexei.Polkhanov on May 21, 2014, 12:42:04 amThanks for the info... made me feel better about spending a couple of hours getting there and back, giving $35 away just so he poked a few keys on some kind of computer terminal connected to an outlet near the engine.Changing the battery is not the hard part (the weight made it difficult). I was very uncertain since Sears Auto (presumably knows more about cars than I do) put in one 6 or 7 years back and it lasted a month. With a "presumed pro-shop" muck up, so I was rather lacking confidence.Time will tell. That Diehard lasted me just a month back then. I will declare victory in say 3 months.

author: Nerull
author_rank: Frequent Contributor
timestamp: May 21, 2014, 02:03:26 am
content: Quote from: NiHaoMike on May 11, 2014, 04:00:19 pmIt's pretty common for boats to have at least a deep cycle battery and a "starter" battery. The boats electronics run from the deep cycle when there is no engine power, and the regular battery is used to start the engine.

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: May 21, 2014, 07:34:40 am
content: Quote from: Rick Law on May 21, 2014, 01:17:02 amHmm, something must have been wrong with battery, it was not charged properly first time perhaps, there was a short somewhere in a car or something else killed it. I would not trust places like Sears to do repairs on my car even if it is just a battery. I would assume they also do few basic diagnostic checks before and after they install it unless they just want to sell the battery.

author: amyk
author_rank: Super Contributor
timestamp: May 21, 2014, 08:21:58 pm
content: Quote from: Alexei.Polkhanov on May 21, 2014, 12:42:04 amWow, what a way to overcomplicate things... these are lead-acid batteries, right? The same chemistry that has been in use for nearly a century, and have not needed much more than a voltage regulator to be kept charged?

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: May 21, 2014, 09:02:17 pm
content: Quote from: amyk on May 21, 2014, 08:21:58 pmWell I don't thing before there was any regulator at all - just a cut-off circuit that disconnects output from alternator (car generator) to battery when it is charged. And before then cars did not have any battery at all - you have to use crank handle to start your engine. Diesel engines can run without any electrical components at all and often use small gasoline engine as starter. So at some point in past having battery and electric starter was a way to complicate things and so on ...Nobody wants unnecessary complications but if it prolongs battery life span by 3-4 years then why not?

author: dannyf
author_rank: Super Contributor
timestamp: May 22, 2014, 11:33:24 am
content: QuoteIt is very sophisticated. In accident, the battery will be disconnected automagically so avoid fire caused by the battery.The rear panels can reconfigure itself to use other lights as signal / brake lights if the original signal / brake lights are burned out.That's in part what you pay for them.

author: ConKbot
author_rank: Super Contributor
timestamp: May 22, 2014, 03:15:40 pm
content: Quote from: dannyf on May 22, 2014, 11:33:24 amOr so you have to buy a battery switch controller module after it fails and your car wont even unlock with the key fob, let alone try to startQuote from: dannyf on May 22, 2014, 11:33:24 amOr so you have the pleasure of buying a new 'rear body control module lighting driver module assembly' when it failsQuote from: dannyf on May 22, 2014, 11:33:24 amYoure paying for something alright... Can anyone guess my opinion on german cars and their love for excess amounts of various electronic widget modules?

author: Fraser
author_rank: Super Contributor
timestamp: May 22, 2014, 04:17:28 pm
content: As the owner of a 2005 Audi A4, 2005 Nissan X-Trail and a 1992 Cagiva Mini Moke, I have three car batteries to look afterFirst a comment on car batteries..... they have a very hard life with some owners (like me) doing lots of short journeys that can end up making the battery work for most of its life partially charged, with rarely a long enough run to fully charge it. It's not a great life for a battery, but for decades the simple lead acid wet battery has coped well, and given most owners good service life. Some colleagues at work laughed when they heard that I actually measured the p.d. on my batteries every few months and provided a full charge via a two stage commercial charger. I do look after my poor old car batteries and they repay me with long life. I am still on the original Audi and Nissan batteries and the Moke battery has just been changed due to low capacity....it was 16 years old ! The new battery is higher capacity and cost me GBP40 from a reputable source.Car batteries live quite an abused life, and need to be cared for if maximum life is to be extracted from them....most owners have no wish to lift the bonnet on their car, so the manufacturer has to get clever and do the hard work of car ownership for them wherever possible. I have no problem with that per-se, but when I read that BMW is fitting batteries with some form of logging or ID chip, it makes my blood run cold. WHY is such needed I ask ? One good reason is to force the owner to have the battery changed at the main dealer.....pure profiteering ! $600 for a battery change....daylight robberyThis is getting like inkject cartridges with the host needing to authenticate the part.I am used to my Audi having many microprocessor 'intelligent' modules hanging off of a CAN bus and I am equipped with VAG-COM CAN for doing diagnostics and maintenance, so can't complain. The diagnostic functions available via the OBDII port can be very helpful and can save much time hunting for a fault. BUT including a consumable item such a s a battery in the 'modules' that are 'married' to the car computer is going too far IMHO. What next, registered OEM brake pads, rotors and tyresA friend who works for Audi once told me that they make the most PROFIT in the maintenance workshop. This battery monitoring/profiling crap seems like just another way to suck money out of the owner after the initial sale. Imagine the trouble that there will be further down the line when the cars are older ..... "Sorry Sir your car is old and obsolete....no battery available anymore and the computer will not run without the special battery....car is scrap!OTT I know, but this is already a problem for owners of older 'modern' cars that need replacement ECU's or control modules and are told by the dealer that they are no longer available or that they cost $$$$. My sister in laws BMW Z3 was in an accident and I was amazed at how many parts BMW had ceased to stock or supply. Major parts like body panels etc !Now my little Mini Moke......... she is basically a motorised roller-skate with a 37BHP 998cc 'A' series low compression engine pulling her along. The good power to weight ratio helps performance. She is electric and not electronic and atomises fuel with air in a good old SU carburettor. She has a simple solenoid controlling the battery to the starter motor and an old fashioned alternator charging the battery. All very simple and she starts just as well as my Audi and Nissan. Very little to go wrong, and your average farmer could fix her with fence wire and bailing twineOh and none of my cars give a hoot what battery sits in the engine bay....so long as it supplies the voltage and current required of it for start and run.CAN-Bus and a multitude of microprocessor modules waiting to fail due to dry joints, tin wiskering or age related degradation......progressDon't get me wrong, I love driving modern cars, but sometimes changes are implemented that are not truly for the benefit of the owner/driver.

author: Rick Law
author_rank: Super Contributor
timestamp: May 22, 2014, 04:25:18 pm
content: Quote from: ConKbot on May 22, 2014, 03:15:40 pmConkBot, for my older car, the key mechanically opens the door you inserted the key in, and electronically open the other doors. In an accident, it will release the locks on all doors. The interior driver side mechanical lever opens the door even when locked with double action and unlocks all doors. (Probably works the same on the passenger side, but never tried.)The car will complain when it merely thinks your exterior light failed... Mine did that for years whenever it is about to rain. The dealer thought they fixed that year in and year out... It gets so annoying I got used to ignoring it. I finally nailed that problem -- I found intermittent connections (plural) in the rear light assembly that for some reason gets worst with increased humidity. I have no idea why why humidity has in impact. More likely is humidity might have changed the mechanical pressure in the assembly's mounting.That is all fine and well when it works right. When it doesn't, it is such a headache. My car is almost old enough to vote. In very cold days, I have to first unlock the trunk, then I can unlock the driver side car door...Not a joke... As the car gets older, I wonder if something will actually explode. The seat-belt is equipped with explosive connection (really!) that will automatically pull itself hard to take up the slack in the event of an accident! As the car gets older, I wonder if that will fail one day, while I am happy chucking along, and the darn thing just go kaboom...

author: Rick Law
author_rank: Super Contributor
timestamp: May 22, 2014, 04:52:07 pm
content: Quote from: Aurora on May 22, 2014, 04:17:28 pmAurora, you are right on. (From a car magazine I read a decade ago...) Car dealers in the USA already made more in their service department than sales for over a decade now since the computer age. You can't fix a certain thing with you don't know what that error code means and independent shops have been complaining that manufacturers are not forth coming with non-dealer requesting the info.The old dealer I had was pretty good. I didn't purchase the car from them but they had been my repair shop for years. A kid rear-ended my car. I needed a brake-light assembly (the OEM replacement worked to every detail but fails the computer diagnostic. It is just a damn housing housing the lights, but it continues to report brake light failure while all the lights worked as expected.) My old dealer managed to find one not from BMW, but from a BMW dealer in Germany. This old dealer I used sold out and the new dealer doesn't seem responsive. (I called their service department and 5 transfers later, I got on voice mail...)So, if it happens that I need an odd part, I am done, the car is toasted. In my State, I have bi-annual car inspection for the sticker to make it road-legal. At the inspection station, there is a big sign that "any computer-warning about the car not working, don't even bother trying here". (I forgot the exact wording, but what they mean to say was clear).

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: May 22, 2014, 05:02:47 pm
content: Quote from: Aurora on May 22, 2014, 04:17:28 pmHuh ... you don't have pressure sensors in your tires and brake pads wear sensors? Those sensors are specific for each model as far as I know.

author: dannyf
author_rank: Super Contributor
timestamp: May 22, 2014, 05:14:08 pm
content: I have owned a few BMWs (+ one MB and one Audi): I started with a 330i, then a 530x, a M-coupe (G1, bought used) and a X3M. I really loved them for the comprimises they are: the bmws are 99% of a sportscar is, yet you can take friends to lunch in them.Of the bunch, the M-coupe was flawless (I also owned it the shortest). Followed by the 530 and then X3 (some electric / memory issues). The 330i is the most fun to drive, yet the most probamatic (coils, spark plugs, brake systems on four corners, sunroof, front crankshaft sensor, temperature control module, rear coil springs, to name a few).Traded it in to a dealer at $4K (9-year old car, with 30K miles on it). I was afriad of selling it to a private party myself.I loved the BMWs for their brakes, transmissions / engine and suspension. My dream car would be a BMW made by Toyota - I did have a Lotus made by Toyota and loved it.

author: Fraser
author_rank: Super Contributor
timestamp: May 22, 2014, 06:14:17 pm
content: @Alexei.PolkhanovAudi A4 2005....... no tyre pressure sensors and those are part of the wheel rather than the 'consumable' tyreBrake pad wear sensors...sure, my A4 has them, but I can buy non OEM brake pads and rotors from many sources. If these had integrated 'Chips' that married them to the car, non OEM's would need to overcome the chip registration without breaching copyright.Just like inkjet cartridges

author: dannyf
author_rank: Super Contributor
timestamp: May 22, 2014, 08:06:26 pm
content: QuoteOlder cars may not have tire pressure sensors; The pad sensors are simple open wires that get closed by the rotors -> no chips and can be left out of the installation.

author: kolbep
author_rank: Frequent Contributor
timestamp: May 22, 2014, 08:37:17 pm
content: My Brother in law was telling me how upset he was about his car.It is ready for him to pay the R7000 ($678) before he collects it.It is a BMW (Ugly darkish green colour, but anyway),Apparently he blew all the chips in the ECU, and some of them were performance mod chips..Asked him how he did that, and he said that the mechanic mentioned that he must not swap the battery around too much (which he had to do several times, because his company bakkie had a bad battery, and whenever his own car ran out of petrol, he would swap batteries and then use the bakkie),Anyway, I doubted that it was swapping the battery too often that did it, so I asked him 'Was the Engine running one of the times you swapped the batteries?' And Guess Whathe had.Just so you all know. with the newer cars, you cannot start them, pull the battery out while the engine is running, and expect the alternator to power it until you get the other battery in. If you drop the +ve Battery Cable, you can kiss your alternators regulator goodbye. And if you do not drop the cable, you are loosing the Ballast that the battery provides, so your voltage can shoot high (until it blows the ECU, which causes the engine to stop, which causes the Alternator to Stop, which means you have no power, and you need a new ECU.

author: dannyf
author_rank: Super Contributor
timestamp: May 22, 2014, 11:47:47 pm
content: QuoteI have done that on some newer cars: a 2009 BMW (X3), a 2010 Nissan (G30), a 2013 Toyota (Landcruiser). and numerous times on older cars.No problem whatsoever. You obviously cannot short the battery but taking out the battery after the car started running hasn't been a problem for me.

author: Fraser
author_rank: Super Contributor
timestamp: May 23, 2014, 12:28:09 am
content: It is correct to say that the lead acid car battery acts as a supply 'load' + Smoothing element + spike suppressor on a car electrical system. Running a car without a car battery in circuit is definitely possible but it does present a risk to very sensitive electronics. Thankfully car electronics are often well protected against noise and spikes as the manufacturer of such modules knows that a car is a relatively hostile environment in terms of supply quality. I can believe that removing the battery in some cars risks damage to the ECU however.As a side note, Tektronix used the Ni-Cd batteries in their early portable oscilloscopes in a similar way. the 110V supply was dropped to the LT voltage by a capacitive dropper circuit and rectified. The batteries formed part of the smoothing and voltage regulation circuit. If you switched such a unit on without the batteries fitted, you let the magic smoke out !