for the past two days i've been noticing a serous battery drain on my phone. due to my class schedule my usage has been essentially the same everyday and nothing has really changed these past two days. I have noticed that with the battery drain is a serious shift in battery usage percentage. Normally, its like 40% screen, 25% android OS and 15% android system...and then a little bit of everything else. The past two days however, its been 60% android OS for the day... I haven't downloaded any new apps...so whats going on? I've tried restarting my phone and such...no change...