I know, not another iPhone battery thread! I've read pretty much all of them in search of help, but this one is beyond me. The phone: iPhone 5, 64GB. The battery was replaced earlier this year and, according to Coconut battery, is still at 100% of original capacity. Up until a couple of weeks ago, I was regularly getting the following out of the phone, with 10% still to go: Usage 8.5 hours Standby 32.5 hours Suddenly this has dropped massively, whereby I'm getting on average Usage 2 hours Standby 10 hours The percentage of battery useage per app shows no abnormalities. I have tried restoring the phone, and setting it up both from a backup and as a new device. I've turned off the myriad of settings the various threads suggest, but to no avail. The most baffling thing is there is still enormous battery drain in flight mode! I put my phone into flight mode at about 11pm with 100% battery. At 7am its dropped to between 40 and 50% ! Useage shows nothing out of the ordinary, the phone is not warm, the battery appears simply to be discharing for some reason. As I say, having tried everything and then some which is suggested elsewhere, I'm pretty baffled. Does anyone have any suggestions? I find the huge drain even in Flight Mode very odd indeed!