This paper presents the details of an optimization method for the solar car's speed and battery management. The optimization method is demonstrated for the World Solar Challenge along a 3000km from Darwin to Adelaide, Australia. The optimization can be performed at any time during the race based on the current location, time, and battery status. The method predicts the required car speeds between the road land marks, taking into consideration the mandatory stops. The optimization includes the terrain inclination, the car rolling resistance and aerodynamic resistance, and predicts available solar energy as function of position and time.