In this paper the design and implementation of an electronic ballast based on a Class E resonant inverter with frequency control, powered by a 12 V battery, is presented. This ballast pretends to be used where a connection to an electric grid is not available. In order to control the output power and compensate the battery voltage variations, the frequency control takes advantage of the Class E resonant tank, changing its input impedance as a function of the switching frequency. Besides keeping a constant luminous intensity in the lamp, the Frequency Control performs the preheating and ignition stages.