JIAHENG JH318 Electric USB Cigarette Lighter Quartz Watch, The watch can be charged through the USB interface by charging line, Imported quartz movement, high precise travel time, Environmentally friendly, without gas, but USB charging, The system starts working when the LED light turn lit during the usage, If the single service time is longer than 15 seconds, the system will stop power transmission automatically and the LED light becomes flashing, The LED light will blink successively in the case of under voltage, which means that batteries are in bad need of recharging, When charging, the LED light will turn lit and it will become dark when the batteries are fully recharged.