Abstract: A capacitor device includes a capacitor unit, a voltage-dividing circuit for outputting a divided voltage obtained by dividing a voltage of the capacitor unit, and a comparator circuit. The comparator circuit causes the charge circuit to operate such that the voltage of the capacitor unit reaches a full-charge voltage. The voltage-dividing circuit includes a semiconductor switching element, and outputs a divided voltage. A control circuit is operable to determine the full-charge voltage to be a high-temperature full-charge voltage by turning off the first semiconductor switching element when a temperature at the capacitor unit exceeds a reference temperature. The control circuit is operable to determine the full-charge voltage to be a low-temperature full-charge voltage that is higher than the high-temperature full-charge voltage by turning on the first semiconductor switching element when the detected temperature is not higher than the reference temperature.

Abstract: In an electrical storage apparatus including an electric storage device connected between a main power supply and a load, a first bypass FET and a bypass diode which are connected in series between the main power supply and the load are provided, and first and second main path FETs connected in series between the electric storage device and the load are provided. A controller judges that the first bypass FET suffers an open-circuit failure if the voltage (Va) of the load is equal to or smaller than the first threshold value Vth1 or if the voltage (Vc) at the connection point between the first bypass FET and the bypass diode is equal to or smaller than the second threshold value Vth2, when the first bypass FET is turned on and the first main path FET and the second main path FET are turned off.

Abstract: In an electrical storage apparatus including an electric storage device connected between a main power supply and a load, a first bypass FET and a bypass diode which are connected in series between the main power supply and the load are provided, and first and second main path FETs connected in series between the electric storage device and the load are provided. A controller judges that the first bypass FET suffers an open-circuit failure if the voltage (Va) of the load is equal to or smaller than the first threshold value Vth1 or if the voltage (Vc) at the connection point between the first bypass FET and the bypass diode is equal to or smaller than the second threshold value Vth2, when the first bypass FET is turned on and the first main path FET and the second main path FET are turned off.