A charging system includes a secondary battery which includes a heat-resistant member between a negative electrode and a positive electrode thereof, a charging-voltage supply section which conducts a constant-voltage charge of the secondary battery, a charge control section which controls the operation of the charging-voltage supply section, and a mode-setting acceptance section which chooses and accepts the setting of either of an ordinary charge mode and a high-voltage charge mode. When the ordinary charge mode is accepted, the charge control section conducts a constant-voltage charge of the secondary battery by supplying a voltage equal to, or below, the reference voltage, and when the high-voltage charge mode is accepted, the charge control section conducts a constant-voltage charge of the secondary battery by supplying a voltage above the reference voltage.