My battery seems well and truely battered right now, can someone explain the proper recalibration technique? As I understand it, you let it run down till it shuts off then charge it up completely. I have done this, however my battery still seems abysmal at about 6 hours. no wifi, no bluetooth. general use. it used to last about 24-35 hours. I did leave it in the sun for 10 mins recently which it came back quite hot but worked perfectly fine, i hear that can damage batteries. what can I do? i don't want to claim on my o2 insurance as a second claim is £50. would apple replace it for me? what implications would this have for o2? thanks, shoot.