The XP10 comes with a new option under SETTINGS–>BATTERY–>REDUCE BATTERY AGING, which limits the maximum battery charge level to 80%. If you engage “Reduce Battery Aging” mode, this will stay active even after a Factory Data Reset, even though the option in SETTINGS–>BATTERY shows that the Reduce Battery Aging is disabled. In this case, ENABLE the option in SETTINGS–>BATTERY menu, then reboot the device and disable the application.