Solar Powered Light Module Kit - TruOpto OP-SLMS001, This simple, yet effective module demonstrates how solar panels can convert the sun's energy into electricity, how it can be stored and how that energy can be released and used when required.In sunny conditions, the Poly-Silicon solar cell converts the sun's radiant energy into 1.8V of electricity which charges the Nickel Hydride rechargeable battery. As the sun's light reduces, so does the output of the solar panel. When the solar panel's output falls below approximately 0.7V, the circuit stops charging the battery and the captured energy remains in the battery. In darkness, the solar cell's output drops to zero which triggers the circuit to switch on the 2 LEDS to provide illumination.The module is supplied ready-assembled. TruOpto OP-SLMS001 Solar Light Module Kit (assembled)