# Reviving lithium batteries



## hardym (Apr 2, 2008)

I've aquired several large bricks of Lithium (Lifepo4) batteries that have 0.5v. These are either in bricks of 18650 or 26650 cells. I have tried putting modest current thru them until they start to get warm. 

Is there any known way to revive them. I saw a utube on freezing ;-)

If I can split the bricks into smaller pieces, would i find that only a handful of the individual cells are bad.... or (probably more likely) is it that once the cells reach 0.5v or lower they are all toast.


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## rmay635703 (Oct 23, 2008)

What voltage are these packs rated at? If they are only the nominal 3.2v you might have half a chance but any more and I don't think lithium likes being fully discharged. 

If they are free try anything you can maybe pulse charging and freezing, who knows?

Good Luck


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## hidbulb (Jan 26, 2009)

nice post!I am actually waiting for the right answers,in case I encounter this I know what to do.


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## Frank (Dec 6, 2008)

I read somewhere that prismatic cells (T-Sky perhaps) can take a very low-amperage charge until voltage rises enough to charge normally. No idea if this concept will work on your batteries! I'd try low current before hammering them with lots of juice though. YMMV


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## ice (Sep 8, 2008)

is it really possible to revive lithium batteries?


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## speculawyer (Feb 10, 2009)

ice said:


> is it really possible to revive lithium batteries?


Yeah, that is what I'm wondering.


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## Greenflight (Sep 13, 2007)

Some people have had luck reviving small lithium polymer cells from extremely low voltages... Not sure if it would work with LiFePos. At any rate there is probably some danger of the battery exploding. Try searching over on rcgroups.com. R/C airplanes use similar chemistry, some what high-performance batteries and I know there's some revival stories on there.

I'm guessing all of the cells will be at that voltage. It's possible that only some of them are bad and that's what caused the rest to fail. I would guess that it would be best to try to revive the cells individually.

Good luck!


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## rctous (Jun 18, 2008)

my experience with A123 cells is that when the voltage gets that low you can charge them up to the 3.65 volts but I find that it gets there without any capacity, in other words if you add a slight load to it the voltage drops like a rock immedialty. I got in a shipment where I had 89 bad A123 cells the factory immediatly sent new replacements. but believe me I spent a week trying to salvage just a couple cells and from all the cells I tried ,,, believe me I tried ,,,none ever recovered to a degree that I could use them for anything, I wound up throwing them all 89 cells away. (that sucked)

Brian


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## ice (Sep 8, 2008)

so even we revive batteries, it is useless right?


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