Cold Temperature Help Revive Batteries?

Hello again,

I keep getting this forwarded email saying that if we leave the 'bad' notebook or cell phone batteries in the feezer for 24hours, it will help revive the batteries (up to 85%). I am not sure if it is true, so decided to ask the pro in this forum.

Thanks in advance.

Oci.

sounds like hogwash to me.
you can store batts in the fridge to slow the self discharge but never heard of doing it to revive them.

I don't know how cold could revive anything.

Agreed with above posts. Horse Hockey.

Horse Hockey?
I thought it was called "horse puckey". /ubbthreads/images/graemlins/wink.gif

But yes, I agree with the other posters - it's just a bunch of horse puckey. /ubbthreads/images/graemlins/grin.gif
You can slow down the self-discharge rate of new disposable batteries by putting them in the fridge, but I don't believe you can actually revive ruined batteries by putting them in the fridge or freezer. /ubbthreads/images/graemlins/icon15.gif

That was a quote from Sherman T. Potter from M*A*S*H

Thanks for the info /ubbthreads/images/graemlins/smile.gif

Oci.

Actually, put your batteries in ZipLock bags to keep the moisture down and super dry. Condensation, liquid, will kill the battery. Freezing the chemical in the battery slows down reactivity but doesn't change the characteristic.

Hey, thought I was the only one who watched that! Haven't quite got to the being able to quote it stage yet though.

As for the low temp battery revival thing, I'd say that it sounds unlikely, not sure if keeping the temp as low as possible while charging might help prevent trouble in the first place though.

Can the battery explode or leak if the electrolyte is frozen because of freezing expansion? You seen the way that ice cubes have a sort of a dome top?

At zero degrees Celsius or 32 degrees Farenheit distilled water will freeze, but the electrolyte in batteries will not. I'm not quite sure what temperature it would actually freeze at, but when it does...yes, you would have some expansion problems. Most likely the ice crystals formed would perforate the ionic membrane and rupture the battery seal, causing leakage and rendering the cell useless. Come to think of it, I don't think I've ever seen any data on the electrolyte (Potassium Hydroxide for Ni-MH, Ni-Cd and Alkaline). Lithiums on the other hand do not use a water-based electrolyte and are therefore not prone to freezing.

Battery revival.........

When I was a kid we had Cox gas-powered model airplanes that used a 6v dry cell to light the glow-plug for starting.

When they went "dead", we drilled a few 1/4" holes in to the top as deep as we could and dribbled saltwater in them to get a few more days use. Anybody remember this?

how about this...I`ve had quite a few friends leave batteries in the freezer only to find out when they tried to use them that they had died. With superconductivity having to do with very low temperatures would this also apply to batteries frozen in the freezer losing their charge?

In the freezer, as opposed to the refrigerator, they can ice over with enough conductivity to slowly discharge as if they were shorted out?

Superconductivity occurs at very low temperature, far lower than in a home freezer.

The idea of ice shorting it out is interesting. I dunno. I've never tried storing batteries in the freezer; I've always kept my batteries in a plastic tray in the hydrator drawer at the bottom of the refrigerator. Everybody in my family has always kept them there, so when I'm visiting relatives if I find they have a dead flashlight I know right where to find the spares. If I ever want to steal their batteries that'll be easy too. /ubbthreads/images/graemlins/naughty.gif

Oh no -- now you all know where I keep my batteries! /ubbthreads/images/graemlins/faint.gif

-Cougar :{)

If the battery is bad, what do you have to loose?

I don't like to tell anybody their wrong unless I know for sure. I have heard very plausible ideas that later turned out very wrong. I have heard some things that seemed so against reason that I have scoffed at them, and later had to eat crow.

What the heck, if you have a bad lithium ion battery, freeze the thing and let us know what happens.

One thing I would not freeze is a dead lead acid battery. Lead acid batteries will freeze when they are dead. Ask anybody who has had to deal with dead car batteries and subzero temps.

I was going to say the same thing (try it!) a week ago...looks like someone beat me to it already. /ubbthreads/images/graemlins/smile.gif

[ QUOTE ]
carbonsparky said:
One thing I would not freeze is a dead lead acid battery. Lead acid batteries will freeze when they are dead. Ask anybody who has had to deal with dead car batteries and subzero temps.

[/ QUOTE ]

Something I would like to add to that is to NEVER try to charge a frozen car battery. Thaw it first or swap with a charged battery. Charging a frozen PB-H2SO4 battery can result in explosion.

What about 123's? Storing them cool/cold help?

[ QUOTE ]
Cougar_Allen said:
Superconductivity occurs at very low temperature, far lower than in a home freezer.


[/ QUOTE ]

Not only that, but it also requires special materials. While the resistivity of most substances decreases with temperature, only a few compounds will ever superconduct.

I have done it many times with nicad tool battery packs. When a pack (room temp)is near the end of it's useful life and inserted into the charger after a few seconds of charging an defective battery pack indicator light will turn on and the charger will turn off. I could repeat this process several times with the same results and with different chargers and packs. I have found that if the battery is placed into a freezer for a few hours and then inserted into the charger the battery will then charge normally. I don't know exactly why it works but I'll take a guess at it... A smart charger may be reading excessive current to the pack indicating a shorted cell. A cold battery would show a sufficient resistance to the charger indicating a normal pack. While the battery is charging and warming up a sufficient surface voltage has built up therefore drawing less current from the charger.