[falcolas]

> avoid spontaneous shutdown when the aged battery can't handle the load

This doesn't make sense to me. I've been playing with LiPo batteries on quadcopters for a few years now, and I've found that battery capacity is directly related to its voltage, and the voltage decreases in a deterministic fashion according to use. High quality and well maintained LiPo batteries just don't behave randomly - that's why we feel safe attaching them to our houses in the form of Tesla Powercells.

Or, in other words, if a phone is showing 40% charge when it shuts down, that's not the battery "spontaneously" being unable to cope with load; that's a bad charge indicator.