Ok so let's say you have your phone on battery for like 14 hours and then you plug it in to charge until it is full. Then you unplug it and then immediately check to see how long it has been running on battery? Why would you do that? Or you are checking it like an hour later and it still has the 14 plus hours listed? Also why are you checking the time on battery while it is plugged in? I have never done that before but I am charging right now and it has the time I had it on battery for listed and it just stays at that number. Now when I unplug and keep looking at it it does continue the original count. rather than resetting it. My guess is it has to be plugged in for awhile in order for it to reset or fully charged in order for it to reset. Having said all that it is possibly designed that way as they changed the name from Time since Unplugged to Time on Battery. Again not sure why it matters.