I have been having issues with my Thunderbolt since the ice cream sandwich update which only got worse with the second update ICS that said it would stabilize the system in early April. My battery life has gone from bad to pathetic. After 3.5 hours of doing nothing, the battery is over 80% drained. Looking at what is using the battery shows that it is 90% system overhead (phone idle, etc), not apps or screen. The phone is sluggish and unresponsive since the first ICS update, pressing buttons takes forever for the phone to accomplish a task. The phone also shuts off on it's own, even when charging.
How do we revert back from this terrible "update"?