Since the update was installed on my Bionic... the battery life went from tolerable (a little less than a day) to unacceptable. Anyone else have this problem? It was fine until yesterday AM when the update was installed and it went to zero in about 3 hours and even though charging for the last two hours... only at 30%. What the heck?
There are topics on this. Search is your friend. After a major software update it is always recommended to do a hard reset. You want to back up your data first. And there are threads on how to do that as well.
One battery-life effect that "optimization" won't cure is that ICS forces you to use 4G/LTE (if available), and that uses more power than 3G. The option for CDMA-only is not offered anymore.
There are, however, ways around this limitation -- which I've applied -- so now I'm happy.
I've noticed my battery life has been pretty dismal since I installed ICS too. I can't pin down what's draining it. I'm really hoping it is just "optimizing" and that it'll calm down soon. Or that I'm playing with it more than I normally do. I've had ICS for less than 36 hours...I've already noticed some performance improvements but my battery still is noticeably worse. I didn't have too many problems with 4G inconsistency before - it seems to drop less than it used to but I don't think that's the main reason my battery is depleting so quickly.