Battery life appears really poor. Having charged this to 100%, It's showing it's been on for For 6 hrs, and battery is at 88%. Checking the battery level brought it down from 90% when I woke it up. Surely this suggests there is something wrong with my battery? At this rate, the phone would not come close to lasting a day without a charge on light use. Power saving and auto brightness are on. Any ideas? If this is the way it works, then I'm afraid back it goes. That's much worse than my IPhone 4. Much worse. I have a SD CARD in. Is that making a difference?