'Repairing' a shorted li-poly battery?

TheFoo

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Oct 28, 2008
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Hi all,

I just managed to short circuit my Ay-Up battery while doing some ad-hoc wiring (carelessly left it on, my fault!)

It now seems dead to all intents and purposes (multimeter & light unit check).

Presumably the protection circuitry has kicked in and stopped everything exploding - this is great, but I'd really like to get it back in working order if such a thing is possible!

Will it do any harm to try it in the charger? Are there any other steps I could take, or do I need to bin it?

Thanks!
 

csshih

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why can't you just make it into an unprotected battery?
(by taking out the protection circuit)
 

qwertyydude

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Shouldn't the protection circuit protect it from this? I know if I short out my cells or try to draw too much current it goes into protection mode and opens the circuit.
 

qwertyydude

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There are no poison gases in lithium batteries, the worst chemical in there is probably the ether used as a lithium salt carrier. The only real risk is high levels of lithium exposure for pregnant women, but she'd practically have to eat the battery to suffer from that.
 

g36pilot

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There are no poison gases in lithium batteries, the worst chemical in there is probably the ether used as a lithium salt carrier. The only real risk is high levels of lithium exposure for pregnant women, but she'd practically have to eat the battery to suffer from that.

The above is too broad a statement if your referencing post #6 concerning Li-Po fire & fumes. Until testing is done in that area we don't know what is included in the combustion product.

Early primary lithium battery Material Safety Data Sheet statements did not include the lethality of hydroflouric acid skin contact or combustion fume inhalation so don't rush to conclusion.

Undamaged Li-Po does appear less chemically hazardous than other Lithium battery products.

Li-Po MSDS: http://us.sanyo.com/batteries/pdfs/lipo.pdf

edit: added "combustion fume"
 
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g36pilot

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I'd bin the battery. Even if you reset it or it's protection there may be internal damage making it a higher failure risk.
 

csshih

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I just realized that around a year ago, before I became "educated" in flashlights and batteries,

I was using big batteries out of old laptop packs.
turns out, they are actually unprotected 18650s.

I used to charge them will a wall wart @ 3.6V 500Mah, by splicing the cable and hooking the ends up..

dangerous? :oops:
 

hopkins

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You'd be very likely to get a lung full of the combustion products.
The safety info says when they contact water (in your lungs or eyes)
HF -hydrogen flouride- is produced... and that, my friends, is when the real horror begins.
 

g36pilot

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You'd be very likely to get a lung full of the combustion products.
The safety info says when they contact water (in your lungs or eyes)
HF -hydrogen flouride- is produced... and that, my friends, is when the real horror begins.


From section V of the LiPo MSDS:

Specific hazards: If the electrolyte contacts with water, it may generate detrimental hydrogen fluoride.



HF: HydroFluric Acid
 
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TheFoo

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Oct 28, 2008
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Hi guys,

Thanks for all your responses.

In the end the charger seemed able to reset the protection circuitry and the battery has seemed fine.

Just lucky I guess! I'll be more careful with the soldering iron in future :thumbsup:
 
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