[suicideneil]

Good question. I dont believe they ( old lipos ) will become dangerous or unstable as such, they just loose performance and will start running hotter- 2 years does seem to be about average lifespan which is one of the few things I dont really like about lipos ( having cheap lipos from places like hobbyking is nice though ). ~120 if fine temps wise, not much you can do really apart from monitor them and maybe use them in less intensive applications until such a time that they run too hot or power is so poor that they arent worth keeping..