Fix lithium 12v battery?

[Andrew1289]

Hey, just messing around.....

Pulled apart a 12v lithium battery. It was 3 volts. Tried to charge it, no change. Cut it open, saw water damage.

Pulled it apart further. 8 battery cells.

Can anyone give me the specs on the battery cells? Im in a location to get all types of battery type stuff cheap and fast. I don't think ill ever use the battery on anything important. Just learning, experimenting.

photos show everything

 

[Storbeck]

I would start by googling every number or marking that you find on the cells or anywhere on the battery in every configuration you can (like leaving off prefixes or adding spaces and stuff like that). Try adding in keywords like "battery" or "cell" or "lithium" and so on.

Those are obviously lithium polymer cells, you could also study up on them and see if there is some sort of standardized sizing that is common, like the number on there 8057120 might have some generic meaning, maybe the length, width, thickness is 80x57x12 or some such combination.

This is fairly basic "detective work"

And finally, these things can be dangerous. Be careful. It's kind of a "if you don't know what you're doing you shouldn't be doing it" sort of thing, but you can choose your own level of risk, make sure you are as educated as you can be about proper handling, tons of information out there on the web just have to go sift through it.

 

[mikidymac]

The cells are 3.7V average each with 2 in parallel and 4 sets of 2. So (3.7-3.7)+(3.7-3.7)+(3.7-3.7)+(3.7-3.7) = (3.7)+(3.7)+(3.7)+(3.7) = 14.80V. If they are 3.0V and lower they are damaged and junk and you don't want to charge over 16.8V. This is why it is very easy to damage these batteries because everyone thinks they should be 12V but by the time you drop to 12.0V on these they are already ruined and will not come back. Also the automatic battery chargers like the Battery Tenders don't work because they switch off and think they are charged at too low of a voltage for the Lipo's. Then you can get all into balancing cells and all that if you really want to.

 

[Freakie]

The circuit board in the battery will prevent any charger from charging the cells if they are below 3.3 volts......it does this to ensure that current cannot go into a faulty cell and cause a rather spontaneous fire. However, you could simply have discharged the battery completely by leaving it connected to a source draining it down completely....it may not be destroyed at all yet, ....typically if you see a bulging cell...then that cell is toasted....none of your appear to be bulging which is a good sign......There are ways to bring back a Lipo from being dead safely if you know what you are doing .....by using a very low current (0,2 Amp ) and bypassing the circuit board initially......u can either charge each cell individually or all together....once each cell is above 3,3 volts (which should not take very long at all (minutes not hours)...then you can use a Lipo charger specific for that battery to charge it to full capacity and balance each cell correctly......If you have repeatedly over discharged a Lipo.....they will fail to come back to life at some point. if any single cell does not lift its voltage to 3,3 volts or more after you have given it 0,2 Amps for say 20 mins.....its dead. FYI.... i wont use Lipo at all in a ski.,,,of course in RC cars, etc. yes...thats where they are the best thing ever.

 

[NathanMoore]

Hey thats my battery!

I ran that battery in my dasa 1200 with total loss for about 3 years, been awesome and extremely reliable even after being drained flat plenty of times. Always charged with a lithium charger, but eventually stopped holding enough charge to crank the ski over. Had a good life, but don't think it's coming back.

 

[Andrew1289]

Nate, your old battery died from water intrusion