EEVblog #865 - How To Increase Alkaline Battery Capacity - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: April 01, 2016, 08:12:26 am
content: Dave shows you an interesting ionic resistance phenomenon that lets you increase the battery capacity in typical Alkaline AA and AAA cells.

author: tszaboo
author_rank: Super Contributor
timestamp: April 01, 2016, 08:34:57 am
content: Hmmm... Is this real?

author: Muttley Snickers
author_rank: Unknown
timestamp: April 01, 2016, 08:42:50 am
content: It wasn't made clear in the video nor was it particularly visible but I can only assume that you had rubber or plastic soft jaws in the vise so as not to short out the battery, others may not be aware of this and may not get the same result because of it.

author: han
author_rank: Frequent Contributor
timestamp: April 01, 2016, 08:58:23 am
content: I use to make dent in larger battery (D size) and can make the battery life again for some time.so i call it's not a April mop

author: sleary78
author_rank: Unknown
timestamp: April 01, 2016, 08:59:17 am
content: I just tried this... works.

author: EEVblog
author_rank: Unknown
timestamp: April 01, 2016, 09:09:04 am
content: Quote from: Muttley Snickers on April 01, 2016, 08:42:50 amYes, forgot to mention this, you can see my electrical tape in the video. Annotation added.

author: plazma
author_rank: Frequent Contributor
timestamp: April 01, 2016, 09:22:43 am
content: Just heard a similar case from a battery specialist yesterday. The lithium battery internal resistance decreases with applied pressure.

author: tszaboo
author_rank: Super Contributor
timestamp: April 01, 2016, 09:25:52 am
content: Quote from: han on April 01, 2016, 08:58:23 amNow I'm just wondering if it is the pressure inside the battery which is causing this. And if you cool down a battery, because of thermal expansion (well, reverse) of different materials cause the pressure to drop and that is why batteries have reduced life in the cold. Besides higher self discharge.

author: danielschroeder
author_rank: Newbie
timestamp: April 01, 2016, 09:45:30 am
content: Hi!What happended at round about 9:37 to the curve on the multimeter?It seems the battery did cut of some minutes? ago and some additional power source was connected?edit: typo

author: MatthewMorgan
author_rank: Regular Contributor
timestamp: April 01, 2016, 09:48:49 am
content: Appers to be April fools as it is not connected to sense:

author: StuUK
author_rank: Frequent Contributor
timestamp: April 01, 2016, 10:05:41 am
content: I feel a new kickstarter coming on. The 'BatteryViseor'

author: Ivan7enych
author_rank: Regular Contributor
timestamp: April 01, 2016, 10:12:53 am
content: Quote from: MatthewMorgan on April 01, 2016, 09:48:49 amSense was connected to Load (to correctly cut off at 0.1V), not to multimeter - it doesn't draw any current from battery and don't need sense.

author: EEVblog
author_rank: Unknown
timestamp: April 01, 2016, 10:39:53 am
content: Quote from: danielschroeder on April 01, 2016, 09:45:30 amNo, the battery stopped discharging and the voltage recovered, just like it's supposed to. I think I had some commentary on this, but it might have got edited out.

author: EEVblog
author_rank: Unknown
timestamp: April 01, 2016, 10:42:28 am
content: Quote from: MatthewMorgan on April 01, 2016, 09:48:49 amThe multimeter does not need and cannot use a sense line, that's only applicable if you make 4 terminal resistance measurements.

author: MatthewMorgan
author_rank: Regular Contributor
timestamp: April 01, 2016, 10:48:00 am
content: Im always spetical of everything near the 1st of April.You where talking about the other 2 cables on the video?

author: MK14
author_rank: Super Contributor
timestamp: April 01, 2016, 10:53:18 am
content: Make a new version of the batterizer, out of the secret Easter egg feature of all 555 timers, and a new spring clamped battery holder, which automatically squeezes every last drop of juice out of the battery.Hence a x1,600% super batterizer.Which can then double the all important battery life, of the EEVblog, upcoming "new version" multimeter.It can even be used to light up the new EEVblog recommended/branded solar roads, both creating free, nighttime perpetual energy, and lighting up the way for motorists, to safely traverse the road.

author: Taucher
author_rank: Frequent Contributor
timestamp: April 01, 2016, 11:27:10 am
content: Dave, just HEAT the battery - should give a similar resultPS:Also nice demo: take a metal bar (1-2m long), clip its ends to a DVM and slam it axially into some hard object - voltage spike

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: April 01, 2016, 11:31:14 am
content: funny enough, for years some ppl i know chew their tv remote control after they stop working and they say it give it a bit of extra life !! i was like what a dump thing to do ... i think i have to apologize now. it's proved by proper testing

author: Ivan7enych
author_rank: Regular Contributor
timestamp: April 01, 2016, 11:56:41 am
content: Dave, can you try charging the alkaline battery? Can it at least partially restore its charge? Or charging them is unpractical waste of time and energy.My children doesn't differ alkaline AA batteries from rechargeable AA cells, and often puts dead alkaline batteries into universal NiCd-NiMeH charger, and it brings some charge into it, at least for small currents.

author: MK14
author_rank: Super Contributor
timestamp: April 01, 2016, 12:05:01 pm
content: Quote from: Ivan7enych on April 01, 2016, 11:56:41 amI'd STRONGLY recommend AGAINST doing that. It can make the batteries leak, badly. Potentially ruining equipment, and costing a lot more (in damage) than buying the correct alkaline or rechargeable batteries. It may even be an explosion risk (dangerous), I'm NOT SURE ?

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: April 01, 2016, 12:06:13 pm
content: Quote from: Ivan7enych on April 01, 2016, 11:56:41 amdid that so many time, it make battery last for longer periods. i did that mainly for my wireless mouse, while a fresh battery may last up to 4 month, doing that make it last for a couple of weeks. it obsiouly heat-up as hell sometimes.Quote from: Taucher on April 01, 2016, 11:27:10 amcould be just the heating effect as @taucher said.

author: hayatepilot
author_rank: Frequent Contributor
timestamp: April 01, 2016, 12:09:17 pm
content: Quote from: Ivan7enych on April 01, 2016, 11:56:41 amBut then the batteries will leak after a while.Happened more than once to me after I thought I could use the batteries longer in a remote control by charging them for a couple of minutes.Makes a horrible mess and I stopped charging alkalines when I realized they leak because of the charging.Greetings

author: Muttley Snickers
author_rank: Unknown
timestamp: April 01, 2016, 12:47:47 pm
content: These ridiculous devices were available many years ago and I only bought one to conduct some tests and also they were clearing them out for about 10 bucks each, never had a battery leak whilst charging even for long periods and some batteries would actually regain a slight boost but never enough to warrant the messing around, I still have it with the booklet and they were intended for use with carbon and I think maybe alkaline batteries, occasionally I still use it for rechargeable's without any problems.

author: Fungus
author_rank: Super Contributor
timestamp: April 01, 2016, 01:02:36 pm
content: So .... putting a bigger spring in the battery compartment could give more benefit that a Batteriser?Edit: I just saw somebody else already posted this idea.And, for the pedants: I know that "bigger" isn't the same as "stronger" when it comes to springs.

author: coppice
author_rank: Super Contributor
timestamp: April 01, 2016, 01:16:24 pm
content: Quote from: Fungus on April 01, 2016, 01:02:36 pmIsn't that the technique used by the Batteriser?

author: Fungus
author_rank: Super Contributor
timestamp: April 01, 2016, 01:16:29 pm
content: Quote from: hayatepilot on April 01, 2016, 12:09:17 pmA normal charger will apply far too much current.I wonder if a special slow charger could be made for alkalines. It might be worth it even if you could only recharge them to 50% a couple of times, that's still double the battery life.

author: Ivan7enych
author_rank: Regular Contributor
timestamp: April 01, 2016, 01:28:20 pm
content: I had no battery leaked after accidental charging, may be it depends on charger type.I remember some advice from very old russian electronics journal (1980th), nonrechrgeable could be charged with alternative current, for example 20ms charging, then 10ms discharging with the same current, or time intervals can be equal but charge current should be higher than discharge current.Anyway, I don't advice anyone to repeat my crazy ideas, I see Dave is checking some (how to tell that?) unusual experiments, and simply ask him to check another unusual thing.

author: elliottveares
author_rank: Contributor
timestamp: April 01, 2016, 01:28:43 pm
content: Not Again!Dave, Best not to include the phrase "april fools" in your video tags if you want to fool us.

author: n3vti
author_rank: Contributor
timestamp: April 01, 2016, 01:47:50 pm
content: Quote from: Fungus on April 01, 2016, 01:16:29 pmAs I recall, there was one made before. Rayovac made a special charger for such batteries. It only sold for a couple of years (around 2000) before it disappeared. I called BS on it back then.

author: MK14
author_rank: Super Contributor
timestamp: April 01, 2016, 01:55:44 pm
content: Quote from: n3vti on April 01, 2016, 01:47:50 pmThere was a time (possibly the date you mention), when SPECIAL alkaline rechargeable batteries were released. They had the advantage of being the full 1.5V (rather than 1.2V), but could only be recharged, a claimed 10..20 times. They also kept their charge for a long time, such as 5 years, which back then was very good. As Nicads etc would loose charge fairly quickly, even if NOT being used.I think Rayovac was one of the main names, who did them. (But I also vaguely remember chargers for charging non-rechargeable alkalines, but they were reputed to be mostly a waste of time and/or con).EDIT: (wrong picture).EDIT2: Correct picture put in now.Here we go...http://www.amazon.co.uk/Rayovac-Alkali-Rechargeable-battery-1-5volts/dp/B0026WHNRI

author: Fungus
author_rank: Super Contributor
timestamp: April 01, 2016, 02:02:36 pm
content: Quote from: elliottveares on April 01, 2016, 01:28:43 pmWas it posted on April Fools day? I though it was only until midday, after that the 'fool' is the person playing the trick.Maybe it's different in Australia.PS: I've heard of bashing batteries to get more life so this video didn't seemtoounbelievable.

author: ElektronikLabor
author_rank: Regular Contributor
timestamp: April 01, 2016, 02:37:19 pm
content: I don't know if it's an april fool or not, but since I was a kid I sometimes squeez old batteries to get some extra capacity out of it.It was a matter of common knowledge in the former Soviet Union to squeze batteries to refresh them.I often asked my self if it's just an illusion or if that really have any effect.

author: Muttley Snickers
author_rank: Unknown
timestamp: April 01, 2016, 02:38:18 pm
content: It would appear that these primary cell charger/ re-generators are still around and the sales spin sounds all too familiar, might have to ship one up to Dave as they are a local product and if it's all bullshit then it can go back in bits.Radio Partshttp://www.radioparts.com.au/product/03611050/lcd883-rezap-universal-battery-doctor-5-in-1-multi-chemistry-charger#.Vv6EBZx94dURezaphttp://www.rezap.com.au/product.htm

author: MK14
author_rank: Super Contributor
timestamp: April 01, 2016, 02:56:23 pm
content: Quote from: Muttley Snickers on April 01, 2016, 02:38:18 pmIt's got only one (on their own websites) review, which is saying that the batteries corroded (ie. it LEAKS) things badly, if left for a long while.tl;drAs I said before, it makes the batteries leak, which is no good.But you can raise a counter point. Which is that batteries can leak anyway. In my experience trying to recharge "non-rechargeable" batteries, gives very little or no success, and seems to significantly increase the frequency and extent, of battery leakage. In some cases, even leaking while charging.http://www.radioparts.com.au/product/03611050/lcd883-rezap-universal-battery-doctor-5-in-1-multi-chemistry-charger#tabs-4Quote

author: Dave
author_rank: Super Contributor
timestamp: April 01, 2016, 02:57:20 pm
content: Hehe, you just injected some current into the system, didn't you? That would explain the change of shape in the discharge curve, as the voltage on the battery would suddenly start dropping more slowly if the current was coming from another source.

author: MK14
author_rank: Super Contributor
timestamp: April 01, 2016, 03:00:57 pm
content: I mentioned that the batteries might/can explode, earlier. Example:QuoteSource:http://www.amazon.com/ReZap-7301-batteries-Discontinued-Manufacturer/product-reviews/B003KGB6Z4/ref=cm_cr_arp_d_hist_1?filterByStar=one_star&pageNumber=1

author: Tek_TDS220
author_rank: Regular Contributor
timestamp: April 01, 2016, 03:12:39 pm
content: I'm not an expert in battery chemistry, but this may have to do with ion diffusion. When you deplete the battery so fast, the ions don't have time to diffuse to the electrodes. Squeezing the batteries causes convection (liquid mixing) that stirs the liquid, quickly moving the ions around and replenishing the battery. You might do better by alternately squeezing and releasing the battery several times.Note that you haven't increased the ultimate capacity. You've only increased the energy output in the short term. If you ran this test once a day (giving diffusion time to mix) I'll bet you find that the total energy output of both batteries is the same.

author: alanb
author_rank: Frequent Contributor
timestamp: April 01, 2016, 03:26:57 pm
content: New Batteriser!

author: Muttley Snickers
author_rank: Unknown
timestamp: April 01, 2016, 03:59:55 pm
content: Quote from: MK14 on April 01, 2016, 03:00:57 pmI don't think that anyone questioned your statement, I certainly didn't and merely pointed out that there are still devices around that promote charging primary cells, also there are many more reviews around on that particular product that aren't very favourable.The difference between this product and say the Batteriser is that this is an actual product which is manufactured and sold by what appears to be a legitimate company and various distributors, if it doesn't work as described or is not safe then the consumer has rights in regards to a refund, in our country anyway.

author: MK14
author_rank: Super Contributor
timestamp: April 01, 2016, 04:16:21 pm
content: Quote from: Muttley Snickers on April 01, 2016, 03:59:55 pmGood post, I Agree!I use to have at least one of those "charge normal batteries" chargers, myself. (From memory...) It basically gave almost no improvement, to run down conventional batteries.E.g. You use your torch/flashlight with brand new (conventional or alkaline, non-rechargeable) batteries, and it runs down (goes very dim), after exactly 5 hours. You immediately set it charging for 6.5 hours. Then immediately try it again in the torch/flashlight. It lights up (not as brightly as normal), for a few minutes, then goes back to being dim.Worse still, on removing the batteries, you can find they are dripping wet, with horrible battery fluid (acid/alkaline/chemicals etc).I think this has similarities to the $1,000 HDMI cables, or $500 oxygen free speaker leads etc etc.Apparently a lot of stuff coming in from China, does NOT appear to meet western modern safety levels. I'm mystified as to how the west is allowing this situation to exist and continue. The items appear to blatantly NOT meet western laws on safety etc.Example: (The following shortish video, looks VERY unsafe!).

author: nidlaX
author_rank: Frequent Contributor
timestamp: April 01, 2016, 04:36:46 pm
content: Quote from: MatthewMorgan on April 01, 2016, 10:48:00 amFour cables going from the battery holder to the electronic load: two for the load input at the front terminals, two for the load sense at one of the rear terminal blocks (essentially the load's internal DVM). Read up on how four wire sensing for resistance measurement works. You're right to be suspicious though...

author: djQUAN
author_rank: Frequent Contributor
timestamp: April 01, 2016, 04:37:16 pm
content: If the video has some truth in it (not april fools) then instead of squeezing the cell, how about putting it in a centrifuge of some sort to compress the electrolyte mix?

author: n3vti
author_rank: Contributor
timestamp: April 01, 2016, 04:44:40 pm
content: Quote from: MK14 on April 01, 2016, 04:16:21 pmThat thing is totally safe!(You'll have a very shocking experience.)But seriously, you have a good point on stuff from China. I've seen a few videos on these and I've even opened a few up. They're thinking cheap cost to make, questionable design, cutting corners, etc. I bet all of us could design something better.

author: ericloewe
author_rank: Unknown
timestamp: April 01, 2016, 04:48:26 pm
content: So... Fake four-wire measurement or the little switcheroo with A "sitting here for a while" when, in fact, it had just been discharged and B had been sitting there?

author: mxmarek
author_rank: Contributor
timestamp: April 01, 2016, 05:02:27 pm
content: The physics behind this is simple. When you squeeze the alkaline battery you put mechanical energy into it. Squeezed atoms are forced to be getting nearer to each other. As you squeeze, also the electrons start to spin faster due to decreased radius of their orbits. This requires a lots of mechanical energy, BUT: Now this extra mechanical energy you just put into the electrolyte, can be extracted as electrical energy!(tm)By this phenomenon new possibilities arise. It is now possible to make high pressure packed batteries. This can be grown into new groundbreaking technology, which can reduce battery size by orders of magnitude for the same capacity, or make the same sized batteries with orders of magnitude more energy!(tm)Unfortunately there is some drawback. If you increase matter density too much, by squeezing in too much power, you can go beyond the critical mass and the battery can implode ruining all the effort (energy) put into squeezing it.God thing is, this energy thou adds to the energy of the void, which with current technology we cannot effectively harvest. Maybe in the future it will be possible to recover it. It could then lead to REAL wireless energy transfer of which Tesla and many other people dreamed.One very good thing about squeezing is The Safety(tm). Properly squeezed batteries cannot make any harm when physically damaged. When battery is damaged and the electrolyte pressure drops rapidly, the temperature will also rapidly decrease. These are known thermodynamics laws. With so much decompression the electrolyte will freeze almost immediately preventing any splashes. The outer foil of the battery can then easily hold frozen electrolyte later, when it heats to ambient temperature, so it will not spill.This safety feature can have another off-prescription usage: as a drink cooler. You get depleted battery, which still have the very high pressurized electrolyte inside, smash it with something to make is decompress and freeze to nearly zero K temperature, and just drop it inside a glass of a drink, for example beer. With that much difference in temperature, freezing is much faster than using standard, old fashioned water ice cubes.I think many brilliant uses for this technology is possible.Cheers!

author: HKJ
author_rank: Super Contributor
timestamp: April 01, 2016, 05:03:25 pm
content: Quote from: ericloewe on April 01, 2016, 04:48:26 pmThe display on the load says "sense", i.e. it is in 4 terminal mode, but there is nothing to prevent a power supply at the back adding some current.And the use of 4 terminal is not really necessary in that setup, most of the resistance is in the battery holder.

author: matkar
author_rank: Regular Contributor
timestamp: April 01, 2016, 05:03:53 pm
content: Quote from: medvedev on April 01, 2016, 02:37:19 pmIt was a common knowledge in Yugoslavia as well. I remember whacking the batteries with a hammer to make the Walkman play again.

author: MK14
author_rank: Super Contributor
timestamp: April 01, 2016, 05:30:18 pm
content: Quote from: n3vti on April 01, 2016, 04:44:40 pmI hope that sooner, rather than later, something is done about it. The fakes and safety risks, are not good. E.g. A fake aircraft part makes it into a jet airliner, and causes mayhem ...................................................................................................Here is an article, describing (amongst other stuff), why you should NEVER recharge, NON-rechargeable batteries.tl;drThey can produce hydrogen gas and EXPLODE.http://www.wthr.com/story/15008952/13-investigates-exploding-alkaline-batteries...............................................................In Dave's video, towards the end, the battery voltage was far too high, for a run down battery (approx 1.25V at about 1800 Sec into test). I.e. I smell a rat. (Tomfoolery/trickery).

author: SteveLy
author_rank: Regular Contributor
timestamp: April 01, 2016, 05:30:40 pm
content: Sqeezing in a vice helps get more energy out of your camping stove gas canister too.

author: ez24
author_rank: Super Contributor
timestamp: April 01, 2016, 05:31:21 pm
content: Quote from: n3vti on April 01, 2016, 01:47:50 pmI bought 8 of these when they came out. Six have been thrown away (bad) but I still have 2 in a lantern that I do not use. Once a year and take them out and the two always have a near full charge. I discharge them and recharge until the next year.If they all lasted list these two they would have become the miracle battery.

author: SeanB
author_rank: Super Contributor
timestamp: April 01, 2016, 05:36:03 pm
content: I did recharge non alkaline zinc carbon cells using rough AC, it did work to extend battery lifetime around 10 times, as the charging extended battery life. Never was a full run time after use, but in place of buying new batteries every week for the radio ( 4 C cells) this allowed them to last around 6 months before they were totally dead. Worked best on the white Everready non alkaline cells, was so so on the black heavy duty ones, and was a definite no go on alkaline cells, as I found out when the first one vented.Basically a half wave rectifier of a 3VAC transformer secondary, with a series charge limiting resistor, and a resistor of around 10-15 times the value across the diode, so it would plate the Zinc case back evenly.

author: mahwe
author_rank: Contributor
timestamp: April 01, 2016, 06:08:05 pm
content: Hi Dave,i build radio controlled airplanes.Some years ago in the time before Lithium Polymer Akkumulators, we used NiCd akkus.There were two big firmes, who build the best Akkus Sanyo and Panasonic.To reduce the battery resistance we pushed them with the help of a big capacity and a hammer.We called it Hammerschlagmethode, it reduced the inner resistor from 8mOhm to nearly nothing.At the end you were able to get 200A out of a 2000mAh Sub C cell.

author: MartinX
author_rank: Regular Contributor
timestamp: April 01, 2016, 07:27:09 pm
content: I think the squeezing work because it redistributes the material inside allowing some unused material in the cell to get into contact with the electrodes, squeezing it in the middle is probably even better than doing it axially, squeeze it rotate it 90 degrees squeeze again and repeat a couple of times to squish around the material inside, you would have to take care not to break the battery or puncture it.Elektor had a long article about their charger design recharging standard alkaline batteries, recharging a fully discharged battery does not work very well because the electrodes are largely consumed, but if you only discharged the batteries to about half their capacity recharging worked very well and it was possible to do this 4-5 times reliably and still have almost full capacity every time, but you could only use half of it every time of course. To be safe charging had to be slow and monitored it took 15 hours or so for a AA battery. Keeping track of the battery status and recharging at he half way point was probably more of a hassle than most people was prepared to endure to save not so much money on batteries.

author: ez24
author_rank: Super Contributor
timestamp: April 01, 2016, 07:48:36 pm
content: This news will probably delay the delivery of the Batterizer, because now they will know to make their device a little shorter to "squeeze" the battery. So they have another excuse for delays.My suggestion is to design in set screws so the screws can be tightened as the battery loses power. It seems carrying around a vise or hammer is a little too much. A small screwdriver would take up much less space.It also seems a good idea for a IG project to make a "battery vise"

author: Fungus
author_rank: Super Contributor
timestamp: April 01, 2016, 08:16:20 pm
content: Quote from: Tek_TDS220 on April 01, 2016, 03:12:39 pmMaybe a motorized battery spinner would work even better. Spin it up to 10,000rpm a couple of times in each direction.

author: Don Hills
author_rank: Regular Contributor
timestamp: April 01, 2016, 09:20:05 pm
content: The problem with squeezing it from the ends is that it can damage the seal and cause leakage. As others have pointed out, squeezing it around the middle is just as effective and safer.

author: ftonello
author_rank: Contributor
timestamp: April 01, 2016, 10:07:48 pm
content: Very interesting!!! Will try this here...But after you posted your video, Batteriser went ahead in a new project to take advantage of this phenomenon....Att

author: kodi
author_rank: Contributor
timestamp: April 02, 2016, 12:51:15 am
content: Quote from: ez24 on April 01, 2016, 05:31:21 pmDON'T! If you have RAMs they are very sensitive to deep discharge. Idea of those rechargeables was sound, their weakness lays in their inability to full recovery from deep discharge. Basically - if you let them discharge up to 60% of original charge, you can recharge them hundreds of times. If you let the charge go lower then we are talking dozens. Full discharge - you can recharge it to full 10/15 maybe 20 times tops.I'm using them mostly in weather stations/sensors as they can really hold the charge for a long time.

author: lwatts666
author_rank: Unknown
timestamp: April 02, 2016, 01:47:01 am
content: OK, No one else has asked, so: How flat do I have to squash my AA's to get 800% more energy out?

author: Little Brutus
author_rank: Unknown
timestamp: April 02, 2016, 02:00:39 am
content: Discharge B (1 hr), Discharge A (1 hr), wait for recovery, Re-discharge A (17 min), Squeeze B in Vice, Re-discharge B.Hmmm, could it be B had at least 1h17m more time to recover than A?

author: Little Brutus
author_rank: Unknown
timestamp: April 02, 2016, 02:07:24 am
content: Quote from: lwatts666 on April 02, 2016, 01:47:01 amBet due to laws of diminishing returns, probably as flat as needed to make it as wide as "Probe's" butt.

author: ez24
author_rank: Super Contributor
timestamp: April 02, 2016, 02:11:41 am
content: Quote from: lwatts666 on April 02, 2016, 01:47:01 amHow big is your sledge hammer? A regular hammer surface area is too small. A hard rubber mallet works best. A 90 degree swing should work with a rubber mallet. A 3 lb sledge hammer should have no more than 45 degrees because the weight of the hammer does the work. You may have to practice on several batteries to get the right results. Be careful not to smash the battery too much because it may not fit.I also suggest running over them with your car. You will need to place a board on them to have enough force. It is best if you cut a V slot in the wood to distribute the force. If you can router a U shape that fits the battery then you should be able to get the 800 % increase (you have to run over them at least 8 times).

author: MK14
author_rank: Super Contributor
timestamp: April 02, 2016, 04:41:55 am
content: Quote from: wilfred on April 01, 2016, 10:51:30 pmThe voltage seemed/seems too high, to recover that much, from being forced down to 0.1V, for a while.But you could be right and/or maybe Dave took a break or something, giving it time to recover.Also the second battery (B ?), had much more time to recover (maybe not, I could be getting confused, because of the sudden time jumps in the video), than the first (A ?). That could also be the main factor in why we got the results shown.Really, both experiments, should occur at exactly the same time, to be fair/accurate. (If you only have one of each of the test items, it is harder to do it at the same time, But still can be (done, by using the wall clock, and doing 2 passes of the experiments), by recording the physical time, and keeping the relative times, about the same, between both batteries. I was not sure, if that was or was not done, for this experiment).BUT I could be misunderstanding the timings, from watching the video. Maybe the timings were NOT that far apart. It is NOT very clear, what the overall timings were (to me, at least).

author: MK14
author_rank: Super Contributor
timestamp: April 02, 2016, 05:12:25 am
content: Quote from: wilfred on April 02, 2016, 04:52:36 amWhat makes you think I have been fooled ?If you search on this subject area (which I did earlier in this thread, but decided NOT to post the results). There are indeed, others, a number of years ago, who discovered similar things. Since their reports are independent and from some time ago, they would appear to at least partially collaborate with some of Dave's findings.My concern, is not so much if it was a trick or NOT. But if you had merely let the "other" (non-physically "squeezed") battery, recover naturally, by just leaving it to rest, for however long that takes. I DON'T know how long it takes, maybe it is 30 minutes or an hour, but could be a completely different time range. It also would have been able to deliver more power.

author: Fungus
author_rank: Super Contributor
timestamp: April 02, 2016, 10:18:21 am
content: Quote from: MK14 on April 02, 2016, 05:12:25 amI'd say the opposite was true. "A" had a least an hour to recover before retesting (while "b" was being drained). "B" had much less time to recover before being squeezed ("A" took only 15 minutes or so to discharge the second time around).nb. This assumes Dave didn't go for lunch between the two re-drains.

author: MK14
author_rank: Super Contributor
timestamp: April 02, 2016, 10:46:48 am
content: Quote from: Fungus on April 02, 2016, 10:18:21 amThe camera angle, suddenly "JUMPS" (so who knows how long, the time delay could be, while the camera was stopped), soon after about 7 minutes in to the video, which is when the batteries are swapped for the second drain test. This is NOT scientific. We (ideally) should know the wall clock time and/or how much time has elapsed for each battery. OR test them simultaneously.Approx 100mA (if I remember correctly from the video, pity it is NOT in text format. It makes it much harder to quickly scan through the details. Sorry) or so apparent capacity change, between the batteries, could just be random variation between them and/or because of timing differences.There is lots of stuff about partially revitalizing spent/used batteries, on the internet, including "SQUEEZING THEM".Example from around 2011 (but there seem to be MANY others):Title: "Why do 'dead' batteries work again after exchanging the places of the batteries in an electronic device?"Quotehttp://physics.stackexchange.com/questions/9887/why-do-dead-batteries-work-again-after-exchanging-the-places-of-the-batteries

author: Little Brutus
author_rank: Unknown
timestamp: April 02, 2016, 12:21:09 pm
content: Quote from: Fungus on April 02, 2016, 10:18:21 amB was drained first, and had at least an hour to recover while A was drained.In the 2nd pass, re-draining, A was done first.

author: apis
author_rank: Super Contributor
timestamp: April 02, 2016, 10:25:59 pm
content: Well, I don't know how/if this really works, but I'm going to guess any way:I suspect it has to do with the structure of the electrodes/electrolyte changing during discharge (becomes grainy or something is forming dendritic structures, etc) this increase internal resistance and prevent free flow of the electrolyte and kills the batteries prematurely. By applying mechanical stress to the battery you might be able to break up the structures somewhat making it possible to extract a few more mA from the battery.

author: jesuscf
author_rank: Frequent Contributor
timestamp: April 03, 2016, 02:56:19 pm
content: If you take a barrel of non-BS and add 0.5% BS to it, it will make the 99.5% non-BS stink like BS. By the way, in many parts of the world there is no such thing as April fools day. Just my 2 cents.

author: SL4P
author_rank: Super Contributor
timestamp: April 03, 2016, 10:27:59 pm
content: Quote from: alanb on April 01, 2016, 03:26:57 pmI like this idea, as it applies pressure around the electrolyte - rather than at the end caps.The end caps of the battery may not compress the chemistry all the way through, and possibly crack or damage the central core electrode.Perhaps a better (one time only) approach could be to 'roll' the battery between three cylinders, increasing the inward pressure slightly over the 'recharging' period - without distorting the original cylindrical profile of the cell.Just a thought.

author: nctnico
author_rank: Super Contributor
timestamp: April 03, 2016, 10:49:46 pm
content: Just wondering how much energy it takes to put pressure onto the battery versus the amount of energy you get in return.

author: Smokey
author_rank: Super Contributor
timestamp: April 04, 2016, 05:21:54 am
content: Quote from: ez24 on April 02, 2016, 02:11:41 am

author: Fungus
author_rank: Super Contributor
timestamp: April 04, 2016, 07:09:24 am
content: Quote from: ez24 on April 02, 2016, 02:11:41 amhttp://www.amazon.com/Ampco-Safety-Tools-H-74FG-Non-Sparking/dp/B000WTPXKQ

author: AndyC_772
author_rank: Super Contributor
timestamp: April 04, 2016, 11:47:32 am
content: QuoteMRI system misbehaving? Not a problem...

author: Fungus
author_rank: Super Contributor
timestamp: April 04, 2016, 06:56:21 pm
content: Quote from: AndyC_772 on April 04, 2016, 11:47:32 amI'm trying to imagine a scenario where you'd want to use a sledgehammer right next to a live MRI machine.

author: SeanB
author_rank: Super Contributor
timestamp: April 04, 2016, 07:14:57 pm
content: Quote from: Fungus on April 04, 2016, 06:56:21 pmGetting the table unstuck after the chair has been slammed into it.

author: Len
author_rank: Frequent Contributor
timestamp: April 04, 2016, 07:30:34 pm
content: Quote from: Fungus on April 04, 2016, 06:56:21 pmIt's a precision instrument, sometimes it needs a little adjustment.

author: Brumby
author_rank: Unknown
timestamp: April 05, 2016, 02:40:02 am
content: I'm getting nervous chills just picturing this scenario .....

author: Barny
author_rank: Frequent Contributor
timestamp: April 05, 2016, 06:14:42 am
content: I've seen an old information movie for kids, where the MRI was explained.(I think it was "Sendung mit der Maus" - broadcast with the mouse)There the moderator held a pice of thick steel chain next to an retired, switched on MRI.It was pulled straight to the center of the scan-chamber, not to the ring itself.They explained they had to search a long time to find an retired one which is still workeing, because the fuleing around with the chain could damage the MRI, even when the chain dont touch it.

author: station240
author_rank: Unknown
timestamp: April 05, 2016, 07:45:13 am
content: Quote from: Fungus on April 04, 2016, 06:56:21 pmThe super conductive magnet is on 24/7/365 as turning it off requires draining the liquid cooling it.Hence even doing work on the floor below requires the special hammer.

author: BigClive
author_rank: Contributor
timestamp: April 06, 2016, 08:52:13 pm
content: Quote from: Fungus on April 01, 2016, 01:16:29 pmI built an experimental charger that trickle charged alkaline cells continuously at very low current in the region of 10mA. It was just a plug-in power supply and a diode, resistor and LED in series with each cell holder.Since alkaline cells lack the chemistry to recombine the gas vented upon charge completion (or possibly even during it) the cells tended to pressurise internally and would sit in the charger and vent randomly with sharp "TCH!" noises. At first I didn't realise what was making the noise until I was next to it and a cell vented. This could also explain why any attempts to recharge alkaline cells often results in them leaking. It's probable that the pressure is violating the seal and pushing electrolyte out.