How can I tell if a Lipoly cell is bad?
 

Hey, so I've had these Maxamps 5s 4000mah packs for awhile (only ran each one once though, and due to a LVC screwup, both packs puffed). I just disassembled the packs and one cell in each of the packs is a bit softer than the others, but none are puffed. (my balancers also showed that only 4 cells were in balance, so one had to be off). Each pack has been fully charged since the puffing (but not run), and they've maintained their voltage. So my question is... how do I tell if a lipo cell is bad? I've been thinking of charging each cell separately, but want to make sure that will help me come to conclusions first. Thanks!

The softer cell will be the bad one obviously, and if you remove the shrinkwrap, and use a voltage checker (plugs into the balance tap), it will read out the voltages of each cell in turn. The bad cell will hold its voltage though, but will always puff up during a run, then settle back down afterwards, as several have reported. I would suggest contacting maxamps about it- you may be able to slpit the packs up and remove the dud cell, though they may be stuck together too well and the dud cell cant be seperated. if you could seperate it, you could build a 4s pack, or simply replace the dud with a new cell, and have a 5s pack again.