Hybrid vehicles can request the necessary power for driving different speed cycles from more than one power source. The combinations of 2 sources offers new possibilities to minimize the fuel consumption of the combustion engine. This paper discusses a systematic optimization strategy for general series hybrid vehicles in combination with a battery. This approach differs fundamentally from other controllers, which are tuned empirically or using little system information. The proposed control strategy is based on the minimization of a objective function, including the combined losses of the combustion engine and the battery. The minimization procedure yields a static controller map, which guarantees both minimal fuel consumption and a balanced state of charge (SOC) of the battery. Simulations and comparisons to other control strategies, with the hybrid vehicle simulation tool ADVISOR conclude the paper.