A battery load leveling system for an electrically powered system in which a battery is subject to intermittent high current loading, the system including a first battery, a second battery, and a load coupled to the batteries. The system includes a passive storage device, a unidirectional conducting apparatus coupled in series electrical circuit with the passive storage device and poled to conduct current from the passive storage device to the load, the series electrical circuit coupled in parallel with the battery such that the passive storage device provides current to the load when the battery terminal voltage is less than voltage on the passive storage device, and a battery switching circuit that connects the first and second batteries in either a lower voltage parallel arrangement or a higher voltage series arrangement.