Put my phone in my locker two hours before I went on break at work, came back and it was hot to the touch, almost too hot to hold, and was giving me warnings of it turning off. It turned itself off before I could see what was going on. Got it home, threw it on the charger, was completely drained. I put it in my locker without anything on, had just sent a text message, went to home screen, and locked it. Set it down and that was it. I had just charged it 3 or so hours before and it was on 100%. What killed my battery life? I checked my battery usage in settings and it was 97% Android OS and 3% something else, forget which and its off to charge up. The hell could have done this? Halp.