Windows Phone users, especially Lumia 920 and 925 users are facing a problem where they experience sudden battery drain for no apparent reason. It is due to stuck process where a process is stuck in the background and continues to use CPU cycles. Using Visual studio to do analysis we see that the phone OS is stuck at 50% and you get a warning of high CPU cycles.
Symptoms of the problem.
Hot back plate
Left metal banding gets unbearably hot
Cannot charge phone as fast