Solar-powered device for charging a battery unit of a mobile telephone handset

A solar-powered device (1) is adapted to be disposed on a battery unit of a mobile telephone handset so as to charge the battery unit (3). The solar-powered device includes a light sensor, a photoelectric converting circuit coupled operably to the light sensor so as to convert light that is sensed by the light sensor into a corresponding current signal, and a current processing circuit, coupled electrically to the photoelectric converting circuit, for receiving and processing the current signal so as to result in a charging current that is adapted to charge the battery unit of the mobile telephone handset.