With moderate usage, I usually end the day with about 60% left on the battery. After installing the KitKat update at 8 a.m., I am now down to 63% on the battery less than 2 hours later, and I suspect I will have to turn off the phone to ensure I have enough juice for the trip home. Location is turned off, I've updated all the apps and rebooted. Otherwise, I basically haven't touched the phone and it's still sitting there draining. What's causing this, and what can I do? This is immensely frustrating.