Unless you're seeing signs that it is puffing, its safe to continue to use. From what I've experienced with my lipos and read, this is normal aging. The cells start losing voltage and capacity. It will continue until they have little useful capacity. If you have a way to charge the lazy cell by itself, it might wake up and it might not. That would let you know if it really is aging or it was something else.


I use my lipos til its no longer worth the time and trouble to charge them for what little I'm getting back out.