The MR-2400 Solar Charger and Battery has been designed to harness the sun's energy or the energy of natural light, shortening the process of transforming it into electricity by using photovoltaic cells (PVs). Here's how it works. Light from the sun hits the solar cells. exciting electrons within the cell. The MyRubberz Solar case is a portable Lithium-ion battery that can be recharged from any USB port or directly from the Sun. Recharge your iPhone 3G or 3Gs ANYWHERE. The MyRubberz Solar case is another performance product to help you continue twittering, facebooking, or just plain simply jamming out to the music that moves you on your iPhone! (currently only in Black but we want to hear what colors you would like)