more than one year ago I bought from HobbyKing 2 Lipos for my Copter... unfortunately due to personal problems I never get to start building the copter and never used them.
Now I was starting to look into that things again, and I was checking everything I had, and I found out that one of them is a bit inflated: not like a balloon, but if I press I can feel the finger going down at least a few mm.
I never charged them so they are as the came from HobbyKing.
I have 2 Turnigy Zippy 2200mAh 3S 25C
Actually I also have a "transmitter pack" 2500 mAh 3C S3, still from Turnigy.
I've checked the cells with a multimeter:
for the healthy batteries the total pack is 11,5V with each cell 3.84-3.85 V each.
The puffed battery has 2 cells with 3.85 V while the 3rd one (actually the one where I can feel the empty space) is 0.6V.
What should I do with that one? Can I use it or recharge it? Shall I dispose it (if so, where should I bring it)?
Unfortunately I live in an apartment in a big city and no yard, or terrace or garden on my property... but it looks like everyone using RC toys are all living in houses with lot of outside space available. I could go to a public park, but I guess police will come and take me to jail if set a battery on fire in a public property :)
I guess I'll cut the connectors, leave it in the salty water bath, and then bring it to the disposal facility.
Yeah, I wanted to try exploding a 4S 5000 battery that had been crash damaged, so I drove a nail through it. I was all dressed up in full welding gear (just short of a bomb disposal suit) with my family watching from a distance and my wife with phone in hand...
Not much happened. I felt like a real dork. :) It smoked a bit, and that was it.
Next time I'll try overcharging it with some long leads.... (I just have to try...)
Mark. The Lipo cell packaging is pretty much watertight. If you don't punch a hole they have to stay in the saltwater for a very long time for the chemistry to be neutralized.
I guess I should build a lipo discharger that connects to the while balancer and then to a car lamp socket :)
I happened to have a Xenon 12V 20W light bulb around, so just soldered some wires on it and connected to the balancing plug just to discharge the 2 healthy cells.
For the moment it's discharging, not very fast, but going down...
Shall I go to 0.0V or under 1V is enough? And shall I also discharge the puffed and damaged cell, or is it safe to leave it at 0.6V?
I think I would follow this advice:
I've seen it, basically I've connected it to one 12V 20W bulb, it was a 2200 mha 3S battery. Took a bit more than 1.2H as he said (when the light went off there was still 1.5V in the battery). I kept it connected (but light was off) another a few hours, and now the total reading is 0.06V (all in one of the 3 cells).
Now connected the leads, and set in a metal box for the night. It puffed a bit during the discharge, but never heated. If it passed the night without exploding (but apparently should not as the voltage is almost ZERO) I'll dispose it in the normal trash.