Throughout the past 3-4 weeks, my battery life on my iPhone 3G has deteriorated and was getting worse by the day. The other day, I fully charged it then left it on standby throughout the night and woke up to see my battery on 20%! I've tried restoring and rejailbreaking (only jailbreaking for the unlock to be sure it's not a Cydia application causing the issue) a number of times, but the problem still exists. Last night I restored and left it overnight with my original Pay as you Go O2 SIM in there, without jailbreaking. The battery only lost 2% throughout the night (according to an app), and even after using Safari and playing some games for about an hour, very little battery was gone! One interesting thing to note is, on the morning when I lost 80% battery, I checked my 'Usage' and apparently I used the phone for 2 hours? All I did was restore and pretty much straight away put it on standby! Does anyone have any ideas what could be causing this? At first I thought perhaps it's my signal, however I always get a very strong reception with my 3 UK sim card (usually 5 bars of 3G). Any ideas would be greatly appreciated. If you need to know I use blacksn0w and blackra1n to unlock/jb. Thanks!