Lawrence Finch wrote:
http://discussions.apple.com/thread.jspa?threadID=2659278&start=150&tstart=0
You must restore as new; if you restore and reload your backup you are just putting the problem back on the phone.
Here's a graduated set of steps to resolve high battery drain. Only go as far as necessary; it is rarely necessary to do all of the steps. After each step reboot the phone (hold HOME and SLEEP until an Apple logo appears, ignoring "Slide to power off"):
1. Settings/General/Reset - Reset
network settings (you will lose WiFi passwords, but nothing else)
2. Settings/General/Reset - Reset
all settings (you will need to reset some additional settings, but will not lose data)
3. If you have Push email accounts: Settings/Mail,Contacts,Calendar - tap on the account name and switch it off (the account, not Push). Open the email app; verify the account is gone (and let the mail app know it is). After rebooting, go back to Settings and turn the account back on. Wait an hour before testing to give it time to sync back to the server.
4. Turn off Notifications in Settings. Test for a day. If the problem has gone away you have an app that is using data when it shouldn't be.
5. If you have EVER launched Game Center go to Settings/General/Restrictions and disable Multiplayer games. You will have to set a passcode to do this; DO NOT FORGET IT.
6. Look at the apps currently in the quick launch bar. When on the Home screen double-press HOME. tap and hold any app so "-" signs appear. Kill any apps that might use background such as Facebook, Skype, Yahoo, music streaming apps, etc.
7. If you have gotten this far and not fixed it you probably need to restore as New.