This was really weird. A couple of days ago, the battery went from 8:00am right through to 5:00am (i.e. 21 hours) with around 2 hours of phone calls, about half with bluetooth, probably 50 texts and maybe 15 minutes of Wifi. After all of that, it still had 50% left according to the battery widget I have. Unbelievable! I had changed nothing from the previous day, in terms of settings, applications etc. The next day, it was back to it's usual 15 hours before getting down to about 10%. I have absolutely no idea why it decided to give me a decent day!!!