I am guessing it's depends on the app is on continuum. I am gonna have Microsoft bingo game to blame as poorly written app using too much resources. Hopefully there isn't any other apps behaving like that as it's not right for battery to continue to drain whilst plugging in mains.no problem when using continuum. the phone is charging when connected to the dock. after sufficiently long period of usage of continuum, your phone's battery will be at 100% when you plug it off from the dock.