My wife's GNex loses battery power at what seems an excessivley fast rate. Last night with the screen off and not being used, it lost 10% in 2 hours. It went from 72% at 10:30pm to 12% at 11:20 am (My S4 drops maybe 20% overnight). What can I turn off or reduce to save battery power? I believe the WiFi and GPS turns off at night (with Timeriffic). Also she works in a building with poor reception.......will that drain the battery at a faster rate (as it keeps searching for a signal?????). Thanks for any help!