My phone keeps draining battery and I'm not even using it. I checked my battery usage and all my apps are fine nothing is sucking battery. I have background refresh on for only one app which isn't even the problem and I have location services greatly reduced to just a few things. I've barely used my phone. I have like almost 7 hours of standby time and 1hr 1/2 of usage and I'm on 55%. Please help.