A charging system, comprising:
- a secondary battery which includes a heat-resistant member having a heat-resistance property between a negative electrode and a positive electrode thereof;
- a charging-voltage supply section which supplies a charging voltage for charging the secondary battery;
- a charge control section which controls the operation of the charging-voltage supply section on the basis of a reference voltage corresponding to the voltage between the negative electrode and the positive electrode in a full-charge state where the lithium-reference electric potential of the negative electrode is substantially zero volts;
- a mode-setting acceptance section which accepts the setting of either of an ordinary charge mode and a high-voltage charge mode;
- a charging-current supply section which supplies a charging current for charging the secondary battery;
- a constant-current charge control section which conducts a constant current charge by allowing the charging-current supply section to supply a predetermined constant current to the secondary battery;
- and
- a voltage detection section which detects a terminal voltage of the secondary battery, wherein:
- if the mode-setting acceptance section accepts the setting of the ordinary charge mode, then the charge control section allows the charging-voltage supply section to supply, to the secondary battery, a first set voltage equal to, or below, the reference voltage as the charging voltage, and if the mode-setting acceptance section accepts the setting of the high-voltage charge mode, then the charge control section allows the charging-voltage supply section to supply, to the secondary battery, a second set voltage above the reference voltage as the charging voltage, so that the secondary battery is charged at a constant voltage charge,
- if the mode-setting acceptance section accepts the setting of the ordinary charge mode and if the terminal voltage detected by the voltage detection section while the constant current charge is being conducted reaches the first set voltage, then the constant-current charge control section stops the constant current charge and the charge control section conducts the constant voltage charge, and
- if the mode-setting acceptance section accepts the setting of the high-voltage charge mode and if the terminal voltage detected by the voltage detection section while the constant current charge is being conducted reaches the second set voltage, then the constant-current charge control section stops the constant current charge and the charge control section conducts the constant voltage charge.