A:Answer Could be defective if it's just shutting off. Reboot it, then check for updates manually to see if there are any bug updates. (Settings - About phone - software updates). If it's still doing it, it may be defective. The battery is the best thing about this model - last a long time. If yours is draining that fast, maybe there's a rogue app running in the background. Close all background apps. Reboot. If it keeps doing it, go to the battery area in Android (settings) and maybe it can tell you what's using so much of it. Turn off stuff you really don't need notifications for, too.
