USST solar powered LED has internal battery. It starts up the circuit work at night automatically. Human body induction functions when people walk through the sensor area, the light is much stronger. It switches to standby mode, when people leave the sensor area after about 5 seconds. At daytime it automatically turns off. It consists of Solar panels: 8V 10W, Lithium ion phosphate battery: 6.4V 9000mAH, maximum power: 15W.