Iphone 4s battery losing charge quickly
I've had my Iphone 4s for about 6 weeks with no problems. In the last few days, my battery is losing the charge really quickly. For instance, after charging all night and making sure it was at 100%, I drove to work (20 min)-without using my phone for anything, and the charge was down to almost 80%. I'm not super tech-savvy, but I've closed everything I can that I'm not using and made sure that nothing is running constantly with no improvement. Any ideas?
iPhone 4S, iOS 5.0.1