US Patent 9235044 Light activated power indicator

A light activated power indicator includes an indicator and a receptor circuit with a light sensitive device electrically connected to the indicator. The light activated power indicator further includes a first terminal electrically coupled to a first end of the receptor circuit and a second terminal electrically coupled to a second end of the receptor circuit wherein the indicator indicates a state of charge of an electrical storage device when the light sensitive device is exposed to one or more wavelengths lying within a response spectrum.