I recently updated my unlocked S2 to 4.0.3 and my phone battery has completely gone! I always clear apps / RAM in the task manager before locking my phone, but my battery seems to be falling so fast! At first I thought it was because 4.0.3 reset my screen brightness quite high. I've put it on automatic brightness like I had before and my screen uses 31% in battery manager and android OS uses 31% too! I've even seen them go up to about 50%! Why is it so high?? Also charging takes forever now..! My battery was on 30% when I started charging it at 9 o clock, it's now 11:30 and it's only on 75% ??