A solar light bar includes a battery isolator adapted to be connected between a bus and a vehicle charging system for isolating a vehicle battery from the bus and for selectively connecting the bus to the charging system. A light source switch connects the light source and the bus for selectively electrically connecting the light source to the bus. When the light source switch is closed, the light source is energized by electricity from at least one of the solar panel, the charging system and the auxiliary battery. When the light source switch is open the light source is isolated from the bus. The auxiliary battery is adapted to be selectively charged by electricity from at least one of the solar panel and the charging system.