EEVblog #865 - How To Increase Alkaline Battery Capacity

[EEVblog]

Dave shows you an interesting ionic resistance phenomenon that lets you increase the battery capacity in typical Alkaline AA and AAA cells.

[tszaboo]

Hmmm... Is this real?

[Muttley Snickers]

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.

[han]

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

[sleary78]

I just tried this... works. 

[EEVblog]

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.

Yes, forgot to mention this, you can see my electrical tape in the video. Annotation added.

[plazma]

Just heard a similar case from a battery specialist yesterday. The lithium battery internal resistance decreases with applied pressure.

[tszaboo]

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

Now 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.

[danielschroeder]

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

[MatthewMorgan]

Appers to be April fools as it is not connected to sense:

[StuUK]

I feel a new kickstarter coming on. The 'BatteryViseor'

[Ivan7enych]

Appers to be April fools as it is not connected to sense:

Sense 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.

[EEVblog]

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?

No, 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.

[EEVblog]

Appers to be April fools as it is not connected to sense:

The multimeter does not need and cannot use a sense line, that's only applicable if you make 4 terminal resistance measurements.

[MatthewMorgan]

Im always spetical of everything near the 1st of  April.
You where talking about the other 2 cables on the video?

[MK14]

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.

[Taucher]

Dave, just HEAT the battery - should give a similar result



PS:
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

[hamdi.tn]

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   

[Ivan7enych]

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.

[MK14]

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.

I'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 ?

[hamdi.tn]

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.

did 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.

Dave, just HEAT the battery - should give a similar result

could be just the heating effect as @taucher said.

[hayatepilot]

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.

But 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

[Muttley Snickers]

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.

[Fungus]

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.

[coppice]

So .... putting a bigger spring in the battery compartment could give more benefit that a Batteriser?

Isn't that the technique used by the Batteriser?

[Fungus]

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.

But 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

A 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.

[Ivan7enych]

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. 

[elliottveares]

Not Again!

Dave, Best not to include the phrase "april fools" in your video tags if you want to fool us.

[n3vti]

A 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.

As 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.   

[MK14]

A 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.

As 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.   

There 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

[Fungus]

Not Again!

Dave, Best not to include the phrase "april fools" in your video tags if you want to fool us.

Was 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 seem too unbelievable. 

[ElektronikLabor]

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.

[Muttley Snickers]

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 Parts
http://www.radioparts.com.au/product/03611050/lcd883-rezap-universal-battery-doctor-5-in-1-multi-chemistry-charger#.Vv6EBZx94dU

Rezap
http://www.rezap.com.au/product.htm

[MK14]

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 Parts
http://www.radioparts.com.au/product/03611050/lcd883-rezap-universal-battery-doctor-5-in-1-multi-chemistry-charger#.Vv6EBZx94dU

Rezap
http://www.rezap.com.au/product.htm

It'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;dr
As 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-4

I have always been impressed with the innovation & money saving value of this product. I first bought this item from a TV marketing site. I used it for five years before its terminals inside the machine became corroded from batteries left in too long (eg: storing the flat batteries in the machine between switching it on to charge). Batteries with some life left recharged the best. Those batteries that were completely flat were difficult to recharge - such as batteries used for x-box games. The older the batteries were the less likely that they would make it beyond half power. It saved me a great deal of money and battery wastage. I recommend it-just watch for corrosion on the batteries being charged.

[Dave]

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.

[MK14]

I mentioned that the batteries might/can explode, earlier. Example:

I used this charger twice. The second time I used it, a "C" battery exploded and I counldn't get all of the corrosive material out. It never worked after that and even if it did, I would not use it again. Would not recommend this product.

Source:

http://www.amazon.com/ReZap-7301-batteries-Discontinued-Manufacturer/product-reviews/B003KGB6Z4/ref=cm_cr_arp_d_hist_1?filterByStar=one_star&pageNumber=1

[Tek_TDS220]

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.

[alanb]

New Batteriser!

[Muttley Snickers]

I mentioned that the batteries might/can explode, earlier.

I 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.     

[MK14]

I 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.   

Good 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!).

[nidlaX]

Im always spetical of everything near the 1st of  April.
You where talking about the other 2 cables on the video?

Four 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...

[djQUAN]

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?

[n3vti]

Example: (The following shortish video, looks VERY unsafe!).

 

That 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.

[ericloewe]

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?

[mxmarek]

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!

[HKJ]

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?

The 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.

[matkar]

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.

It was a common knowledge in Yugoslavia as well. I remember whacking the batteries with a hammer to make the Walkman play again.

[MK14]

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.

I 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;dr
They 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).

[SteveLy]

Sqeezing in a vice helps get more energy out of your camping stove gas canister too.

[ez24]

As 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.   

I 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.

[SeanB]

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.

[mahwe]

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  .

[MartinX]

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.

[ez24]

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" 

[Fungus]

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.

Maybe a motorized battery spinner would work even better. Spin it up to 10,000rpm a couple of times in each direction.

[Don Hills]

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.

[ftonello]

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

[kodi]

I 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.

DON'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.

[lwatts666]

OK, No one else has asked, so: How flat do I have to squash my AA's to get 800% more energy out?

[Little Brutus]

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?

[Little Brutus]

OK, No one else has asked, so: How flat do I have to squash my AA's to get 800% more energy out?

Bet due to laws of diminishing returns, probably as flat as needed to make it as wide as "Probe's" butt.

[ez24]

OK, No one else has asked, so: How flat do I have to squash my AA's to get 800% more energy out?

How 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).

[MK14]

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).

No trickery, the electronic load had switched off because the battery voltage dropped to 0.1V. What you saw was the battery voltage recovering under no load.

The 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).

[MK14]

What you and no one else it seems has realised is that there is no joke. It's not a trick. THAT'S the joke.

What 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.

[Fungus]

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.

I'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.

[MK14]

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.

I'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.

The 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?"

   
I have also read that squeezing them with pliers works, but neither of these cases is relevant to my situation.

http://physics.stackexchange.com/questions/9887/why-do-dead-batteries-work-again-after-exchanging-the-places-of-the-batteries

[Little Brutus]

"A" had a least an hour to recover before retesting (while "b" was being drained).

B 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.

[apis]

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.

[jesuscf]

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.

[SL4P]

New Batteriser!

I 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.

[nctnico]

Just wondering how much energy it takes to put pressure onto the battery versus the amount of energy you get in return.

[Smokey]

OK, No one else has asked, so: How flat do I have to squash my AA's to get 800% more energy out?

How big is your sledge hammer?  .....

[Fungus]

How big is your sledge hammer? 

http://www.amazon.com/Ampco-Safety-Tools-H-74FG-Non-Sparking/dp/B000WTPXKQ

[AndyC_772]

Non-Magnetic for use near highly sensitive magnetic equipment; MRI and Clean Room environments; Corrosion Resistant even in the most severe environments

MRI system misbehaving? Not a problem... 

[Fungus]

Non-Magnetic for use near highly sensitive magnetic equipment; MRI and Clean Room environments; Corrosion Resistant even in the most severe environments

MRI system misbehaving? Not a problem... 

I'm trying to imagine a scenario where you'd want to use a sledgehammer right next to a live MRI machine. 

[SeanB]

I'm trying to imagine a scenario where you'd want to use a sledgehammer right next to a live MRI machine. 

Getting the table unstuck after the chair has been slammed into it.

[Len]

I'm trying to imagine a scenario where you'd want to use a sledgehammer right next to a live MRI machine. 

It's a precision instrument, sometimes it needs a little adjustment.   

[Brumby]

I'm getting nervous chills just picturing this scenario ..... 

[Barny]

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.

[station240]

Non-Magnetic for use near highly sensitive magnetic equipment; MRI and Clean Room environments; Corrosion Resistant even in the most severe environments

I'm trying to imagine a scenario where you'd want to use a sledgehammer right next to a live MRI machine. 

The 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.

[BigClive]

A 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.

I 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.