Abstract: An electrical power conversion system that supplies the maximum available output power from a power source such as a solar array to a plurality of loads such as rechargeable batteries. The output power of the solar array peaks at an optimum current that is less than is maximum available output current. The system includes a controller and a plurality of dc-to-dc converters that charge the batteries. The controller monitors the solar array's output power and adjusts the battery charging by generating a current control signal that tracks a peak of the solar array's available output power and sets a current limit such that the combined current draw of the plurality of dc-to-dc converters is substantially equal to the solar array's optimum current at which it provides its maximum available power. The electrical power and control signals are transmitted from the power source and controller to the power converters on three bus bars, including a power bus, a control bus, and a common bus.