I have noticed since ios 7 update that my ipad mini powers down in different durations. One takes 2 seconds and the other takes 15 seconds. But I did a test to see if I can reproduce the 15 seconds power down. And it seems that I have to power down first when it takes 2 seconds and then power up and then power down again to get the 15 seconds power down. This seems like a real waste of time investigation, but my concern is that I maybe seeing a video of a power down and power up via mirroring. I suspect this because sometimes the battery level indicator changes really fast and when I jump from one app to another the screen goes to an old screen just before updating. Any idea what is going on? Thanks.