My two Android phones are doing the same thing, Motorola Milestone and Samsung GS3. From time to time, it is sleeping in my pocket and it will start to get warm and the battery is then draining quite rapidly. I guess it must be caused by an application that is stuck running in the background so I am checking:
- Task manager, but none of the applications seem to be using more CPU than any other, they are mostly all close to 0%.
- In "Battery Statistics" only "Phone Idle" shows quite high battery usage so it does not tell me if there is a problematic application.
Currently I just reboot the phone to solve the problem but I would prefer if I was able to find the problematic application so I can close it.