Getting another 25% out of alkaline batteries

[sbslider]

I found this today and thought it was worth sharing here. I find this guys sort of annoying, but his method in this video is sound, and it appears that this phenomenon works. Basically beating on mostly discharged batteries allows you to get a fair amount more juice out of them. I suspect the amount depends on several factors, but it is good to know if you really need a bit more life out of a cell . . .

EEVblog #865 - How To Increase Alkaline Battery Capacity

[Angler]

Cliffs notes?

[sbslider]

@Angler

Cliffs notes?

I thought the same thing. Here is one of the comments for the video that is applicable

Very interesting video!
This is a well-known occurrence in batteries with solid particles.

Alkaline batteries (and a great many other batteries) are made with electrodes consisting of powdered zinc for one and powdered carbon and manganese dioxide for the other. Now ideally when you pack them into the battery all the particles in the same electrode will touch and eventually give you a conducting path from every particle to their respective current collector component, a carbon rod or a metal can. BUT, in practice some of the particles will remain suspended in the electrolyte and not conduct. These orphan particles can’t be oxidized/reduced in the electrochemical reactions and thus essentially remain unused. Additionally, during discharge, loosely connected structures of particles will disconnect as the weakest particles get oxidized/reduced first and no longer conduct the current of its neighboring particles. So more orphan particles are created. Eventually all the connected particles are discharged and the battery is dead. But these orphan particles remain.

Compressing, striking, grinding, or even sonicating the battery will dislodge the orphan particles and cause them to connect, forming a low-current path to their respective current collectors and giving some extra capacity. This capacity was always in the battery, it was just unavailable. Continued mechanical action will eventually dislodge all available particles and the battery will truly be dead.

This effect is an active area of battery research as it has implications for the life cycles of rechargeable batteries. When a battery is discharged and recharged the particles don’t quite recrystallize exactly the same way as in the previous cycle and this leads to increased ESR, physical wear of the membranes and components and other problems that contribute to limited numbers of charge/discharge cycles.

Ways to reduce the effect include better manufacturing methods, additives that make the particles stick together better and prevent the weakest particles from disconnecting, as well as advanced charging/discharge circuitry that presents a pulsating load of a special waveform to the battery that discharges the particles more evenly rather than going after the weakest ones first.

Batteries with molten electrodes, fuel cells, all-liquid electrodes and similar chemistries don’t exhibit this particular effect.

[TheBo]

Hei, Thank you for the heads up!! I follow EEVBlog and many others like joe smith which is great but i missed this vid

[The_Miller]

Looking at the size and voltage I decided to try to just charge some really cheap @ss AA alkaline cells when they did not turn on a light anymore

I posted it somewhere but it went a bit like this
New, runtime 100%
First charge, runtime 50%
Second charge, runtime 48%
And at 10 charges it was ~40% I think and then I stopped
Felt the cells the whole time while charging and they didn’t get hot, had the Liitokala dual bay charger on a metal tray.
10 times ~45% ment an extre 4 and a half times of light from the cheap zoomie (that would not have caused bad feelings if it would have broken down during the process ) I thought it was kind of neat. But maybe a bit unresponsable

[LightRider]

@The Miller

Looking at the size and voltage I decided to try to just charge some really cheap @ss AA alkaline cells when they did not turn on a light anymore

I posted it somewhere but it went a bit like this
New, runtime 100%
First charge, runtime 50%
Second charge, runtime 48%
And at 10 charges it was ~40% I think and then I stopped
Felt the cells the whole time while charging and they didn’t get hot, had the Liitokala dual bay charger on a metal tray.
10 times ~45% ment an extre 4 and a half times of light from the cheap zoomie (that would not have caused bad feelings if it would have broken down during the process ) I thought it was kind of neat. But maybe a bit unresponsable

I think there are chargers that do that. They charge very slowly and in cycles of on/off. The results I remember reading were close to what you have recorder.

[cbrake10]

Do you mean charge or discharge Miller? I think I understand but might be confused

[The_Miller]

I charged them and then used a cheapie zoomie to discharge

[hank]

You’d think moving depleted cells into a power tool that vibrates
(stop, I know what you’re thinking)
would extend their life …

[Jensen567]

Alkaline batteries are indeed rechargeable, just with greatly reduced capacity. For kids toys and stuff though they work fine, re use them 5 or 10 times then toss them before they leak. I have done it many times with no problems before. Just don’t try it with lithium primaries…

[hank]

Chuckle.

Compressing, striking, grinding, or even sonicating the [alkaline] battery

In the very old days (1950s) the cheap carbon-zinc cells had a solid carbon rod in the center, and dropping or banging the cell could break that, killing the cell.
https://www.google.com/search?q=carbon-zinc+cell&source=lnms&tbm=isch&sa=X&ved=0ahUKEwitlqKS9tHUAhUF3WMKHTYNC3IQ_AUICigB&biw=1248&bih=824

That design is still in use.

[cbrake10]

Very interesting

[Savydude]

I have heard of this phenomenon, I thought it was just clickbait but it seems not.