I've had my 4S since the day of release. Up until now I've been very happy in terms of battery performance. But starting yesterday my battery is draining at an alarming rate. Earlier when I took it off the charger at 100% it was down to 93% after checking in here in the forums and checking my email. About half an hour later it was down to 83% and as I type this it went down to 81%. I haven't touched anything in settings and I haven't installed any new apps. Actually I did, a new camera app but it's not running in the background. As a matter of fact I made sure to shut down all background apps. Any ideas as to where to look or what to do? Thanks in advance.