Sometimes it is enough to just drain the battery until OS shuts you down and after that let it charge to 100% with no interruptions (best not using the device at that time)
It may need multiple cycles
doing this about once a month should keep the "OS“ of the device (every device with a rechargeable lithium battery (phones, drills, cars, etc.)) calibrated with the actual SoC (state of charge) of the battery.