I had a 2s 5000mah lipo that puffed one cell. This happened after it had been run in my truck to about 3.8 v per cell. When I put it on the shelf it was fine. I came back 3-4 days later and it was puffed up. I put it in a metal coffee can in a bed of rice and set it outside. After about 2 weeks I went to check on it and it was puffed so tight I thought for sure if I touched it, it would pop. So I decided to try to disassemble it and salvage the one cell that had not puffed. In the process of taking everything apart and had already cut off the battery leads, I laid it on the bench and the exposed battery leads came in contact with the wire cutters. Of course sparks flew and I thought at first that I had been shot. Anyway, I decided that i would liquid tape the bare leads to prevent it from happening again, and that I would wait till after it dried to continue to disassemble it. So I went to put it back in the coffee can and noticed that the puff had deflated quite a bit. It did not vent either. So, I am wondering why would a direct short relieve the pressure from the inside the cell without rupturing it? Also, if it deflates back to the original condition, would it be safe to use it?
Thanks for any advise or theory that you may have.
Oh and how should I dispose of the bad cell?