The past two nights I have gone to bed with atleast 50% battery life remaining only to wake up to a dead phone. I charged it this morning and have not used it at all and my battery life is already down to 86%. It says 1hour 13 minutes of usage and 1 hour 13 minutes of standby?? It has been asleep the entire time. Is there an APP that is killing my battery that I am unaware of? Wifi is off, location services is off and phone is asleep??