Major OS battery drain after 47A update

[anjely]

Trying to find advice on what to do with my phone after the 47A update has turned the OS into a nightmare. On idle, the OS uses about 80% of the battery, during moderate use the OS uses slightly more battery than the screen. If I charge to 100% before I go to sleep, in 6 hours my battery will be dead (usually it would still be about 80% by morning). I tried a factory reset but no dice. My phone is not rooted, but considering that I might want to figure out how to root it if I can't figure out this issue soon.