1, Variable Voltage Battery. By pressing the button three times in one second to change the voltage,three options are available for you, 4.8V(White),4.2V(Green),3.7V(Red).
2, 10s-Protection. When press and hold switch for 10s, the battery LED will flash three times to protect.
3, LED Indicator. When the battery LED flashes 15 times,it means the battery is power off. Please charge immediately.