So i have a 4S and i used iOS6.1.3 with no issues and had about 8hours wifi usage. I also used iOS7 beta6 with 7-8hours wifi usage. When the GM released last week i just "updated" my device and instantly got really bad battery life....like only 3-5hours usage. Yesterday i completely RESTORED my 4S and installed nothing on it. And i still only have 3-5hours usage time.... Is there a way to check if my battery is broken?