My iPhone 6 has been through 680 full battery charge cycles and both the battery health app for iPhone and iBackupBot for PC report i still have 95% capacity left. How is it possible for me to only lose 5% after that many cycles when even Apple has claimed that batteries typically lose around 20% by 300-400 cycles? I've had an iPhone 5s with less cycles that was toast which i eventually replaced the battery for, and my dad's 5s is on its last legs at close to a thousand cycles. Did I just get very lucky and happen to have a rare, very healthy battery? My battery life still sucks anyway due to living in a very low signal area.