Hi, Ive heard somewhere that when you discharge your battery (through normal usage) and it shuts off, its actually not really 0%. In fact some of the juice is left. However if you continue to leave your phone in that state, the battery will be slowly discharged and eventually it will empty to a point-of-no-return where no amount of charging will bring it back to life. Is that true? Im asking this because i just got a new phone, and am planning to keep my IP4 (just in case). I do not want to pickup the phone 1 year later, only to find out the battery is completely dead and its unusuable. So if any battery experts can answer, it would be of great help.