I know this has been brought up before. But please look... (Before bed time.) The actual draining had already started before bed time. : : : (Woke up just couple of hours later to check.) ***At this moment, I immediately select the "Air Plane" mode to see if it would still be draining. : : : (So you can see, NO voice NOR data access, but still draining.) My conclusion is that there must be something running in the background.