I am using a mophie air case with my ip4s. I have noticed at times that when I plug it in to charge overnight from my mac air (of course with mophie turned off), the phone seems to drain (I wake up and it is at 97 or 91 percent charged). It had hit 100 before that and the mophie was not used at all during the cycle (so it wasn't charging the mophie first and then the phone). Anyone else have this issue. If I unplug and then replug in it charges back up to 100.