The control unit of a charge control apparatus for controlling charge of a storage battery connected in parallel to a solar cell panel has a voltage detector and a reference voltage generator for generating a reference voltage, both of which are connected in parallel to the storage battery, a delay device for delaying the output signal from the voltage detector by a predetermined time, and a comparator for comparing the signal delayed by the delay device with a reference signal generated by the reference voltage generator and controlling, in accordance with the comparison result, opening/closing of a switch for short-circuiting the output from the solar cell panel. With this simple arrangement, devices in the charge control apparatus can be protected even when the storage battery is disconnected for maintenance or the like.