[SOLUTION] iPhone/iPad/iPod battery drain after iOS 7.1 update
Publicado por Manuel Escudero
I've seen that a lot of users are reporting this particular issue with their iPhones/iPads/iPods after the last iOS update (from 7.0.6 to 7.1) reading around I've found that this issue it's pretty common between OS updates (even more when you do OTA updates) and although it's causes might vary, most of the time it's produced because of a push app that was interrupted in the middle of the update and get's stuck in a loop trying to furfill it's function after it. According to this thread in the Apple support communities the solution in most cases is to reset the iDevice as new after the update (without restoring any backup) and then, try to use it throughout the day. If the problems indeed dissappear, then we can restore our backup and test if everything is back to normal.
NOTE: One indicator that this might be happening to you, it's this "spinning wheel shymphtom" that might indicate an app constantly refreshing (and failing) over and over in a loop if it won't dissappear for a long time (I'm not totally certain about this theory though):
In case that restoring the backup results in a resuming draining, then the backup is corrupt and we need to restore the phone again as new trying to setup everything from the begining by ourselves again instead of restoring a previous backup. You can restore the device directly from Settings>General>Restore and then select the full restore option (Delete settings and contents). After the process it's done, you should setup the iDevice as a new iDevice in the first time assistant that will greet you on that first boot. Remember to have the iDevice plugged to some sort of an energy source for the restoring process.
P.S. In my case, I decided to go with the full restore and manual reset (install app by app, change all the settings again by hand and so) for my iPhone 4S instead of restoring a backup, it seemed to work fine for me; Also remember to apply your normal battery saving routines after the restore (disable bluetooth/3G if it isn't needed, switch to Wi-Fi when at home, disable background refresh etc.), please share your own tests and results in the comments.