Heath Zenith HZ-7163-BK Motion Activated Security Light, 2-Lamp, LED Lamp, 600 Lumens, Plastic Fixture

This light operates from a built-in Lithium-Ion battery charged from a solar panel. It will also hold three "C" alkaline batteries, which are used as a backup power source. If the solar battery becomes depleted, the light will automatically switch to the alkaline batteries. When the solar panel has recharged the solar battery, the light will automatically switch back to the solar battery.