NOVELTY - The controller has a power inverter circuit i.e. voltage fall converter (34), connected to an output terminal of a photovoltaic power generation unit i.e. solar panel (50). A step-up circuit (32a) voltage-rises output electric power (Pbc) of the power inverter circuit and outputs to a vehicle-mounted main engine battery (Bm). An electrical storage unit i.e. sub-battery (Bsb), is connected to an input terminal of the step-up circuit and an output terminal of the power inverter circuit. A control unit controls the output electric power of the step-up circuit to a command value.    USE - Controller for controlling electric power from a solar panel to an electronic device in a vehicle.    ADVANTAGE - The controller controls the output electric power of the step-up circuit according to the command value, while outputting the electric power to a main engine battery side by the step-up circuit such that charging power of the main engine battery and charging/discharging electric power of auxiliary machine battery can be made into a suitable value, so that the generated electric power of the solar panel is settled with maximum electric power point tracking control. The controller sets an upper limit guard value and a minimum guard value, while outputting the electric power to the main engine battery, so that fall of reliability of the auxiliary machine battery is avoided. The controller sets the command value of the output electric power of the step-up circuit to upper limit guard value such that time required to charge the electric power at the main engine battery can be shortened, thus reducing power consumption of the vehicle-mounted electronic device.    DETAILED DESCRIPTION - The control unit is a high-order electronic controller (52) and a drive control part (32b). The sub-battery is a nickel hydride secondary battery and a lithium ion secondary battery. The main engine battery is a lithium ion secondary battery and a nickel hydride secondary battery.    DESCRIPTION OF DRAWING(S) - The drawing shows a circuit block diagram of a vehicle-mounted power controller.    Vehicle-mounted main engine battery (Bm)    Sub-battery (Bsb)    Output electric powers (Pbc, Psp)    Step-up circuit (32a)    Drive control part (32b)    Voltage fall converter (34)    Solar panel (50)    High-order electronic controller (52)