Some embodiments relate to a power generation system. The power generation system includes a first generator and a first battery charger. The first battery charger is adapted to charge a first battery and a second battery. The first battery and the second battery are each adapted to provide power to start the first generator. The power generation system further includes a controller that determines a state of charge for each of the first battery and the second battery. Based on the state of charge for each of the first battery and the second battery, the controller determines which of the first battery and the second battery receives charging current from the first battery charger.