Abstract: The battery charge/discharge testing device includes a sub-charge/discharge unit connected to a main charge/discharge unit through bus lines, wherein when an output voltage of a built-in battery in the sub-charge/discharge unit is in a voltage range capable of supplying power, sub-power supply control is executed to supply discharge power of a built-in battery between the bus lines through a full-bridge circuit in a sub-DC/DC conversion unit by duty-ratio controlling ON/OFF of switching elements of the full-bridge circuit so that the voltage between the bus lines becomes a first predetermined voltage value. When the voltage exceeds the first predetermined voltage value during the sub-power supply control, the control is stopped, and constant current charge control is executed to charge the built-in battery through the full-bridge circuit by using, as a power supply, discharge power of the test battery supplied between the bus lines by duty-ratio controlling ON/OFF of the switching elements.

Abstract: Provided are a used battery unit holder and a used battery unit storage system capable of easily storing and transporting used battery units from various manufactures while suppressing the deterioration of the used battery units during storage. The used battery unit holder is detachably attachable to a storage device for storing multiple used battery units, including: a connection unit for connecting a used battery unit held in the holder through a circuit included in the storage device in such a manner that the used battery unit can be charged and discharged; a battery status recognition unit which recognizes the battery status of the used battery unit; a charge/discharge instruction acquisition unit winch acquires charge/discharge instruction information; and a charge/discharge management unit which discharges from a discharge-target battery unit and charges a charge-target battery unit in a manner to fall within a predetermined SOC range according to the charge/discharge instruction information.

Abstract: Constant current charge control for supplying a charging current of a set current value to a battery by duty-ratio control for a full-bridge circuit is executed. When the voltage between terminals of the battery rises to a set voltage value during the constant current charge control, the constant current charge control is stopped and constant voltage charge control for supplying the charging current to the battery to maintain the voltage between the terminals at the set voltage value is executed. When the charging current drops to zero during the constant voltage charge control, the constant voltage charge control is stopped and zero amp control for maintaining the charging current at zero is executed. When the voltage between the terminals rises above the set voltage value during the zero amp control, the zero amp control is stopped and minute discharge control is executed.

Abstract: There is provided a power converter that is operated by using a power supply of one system and effectively using a current flowing in a load. A charging operation that supplies a charging current and the like to a load 13 and a discharging operation that outputs a discharging current from the load 13 are performed by switching each semiconductor switch of a full-bridge circuit 12. A control section 15 controls all semiconductor switches of the full-bridge circuit 12 to be in an OFF state while switching the charging operation and the discharging operation, makes an inertia current generated by energy accumulated in inductors 27 and 28 flow from a circulation diode of the semiconductor switch that is in OFF-state to a first connection point of the full-bridge circuit 12, and supplies the inertia current to a control power supply section 14 or a DC fan 16 by the reverse flow prevention diode 18.

Abstract: There is provided a power converter that is operated by using a power supply of one system and effectively using a current flowing in a load. A charging operation that supplies a charging current and the like to a load 13 and a discharging operation that outputs a discharging current from the load 13 are performed by switching each semiconductor switch of a full-bridge circuit 12. A control section 15 controls all semiconductor switches of the full-bridge circuit 12 to be in an OFF state while switching the charging operation and the discharging operation, makes an inertia current generated by energy accumulated in inductors 27 and 28 flow from a circulation diode of the semiconductor switch that is in OFF-state to a first connection point of the full-bridge circuit 12, and supplies the inertia current to a control power supply section 14 or a DC fan 16 by the reverse flow prevention diode 18.