Abstract: A battery charging system for a vehicle, capable of charging a vehicle battery pack properly in a short time even during driving a vehicle-mounted electrical load. The battery charging system includes the battery pack mounted in the vehicle, the vehicle-mounted electrical load that can be driven by a current from the battery pack, and a battery charge controller that controls charging of the battery pack. When the battery pack is charged by using an external battery charger during operation of the load, the battery charge controller requires the external battery charger to supply a sum current that is a sum of a current for charging the battery pack and a current for driving the load to the vehicle.

Abstract: A storage battery has at least battery banks, switching units, a charging terminal, a discharging terminal and a battery management unit. The battery banks form a bank structure. Each switching unit electrically connects a group of the battery banks with either the charging terminal or the discharging terminal, and disconnects the group of the battery banks from the charging terminal or the discharging terminal. The battery management unit instructs the switching units to electrically and simultaneously connect one or more battery banks to the charging terminal during charging, and to electrically and simultaneously connect one or more battery banks to the discharging terminal during discharging.

Abstract: A battery charging system for a vehicle, capable of charging a vehicle battery pack properly in a short time even during driving a vehicle-mounted electrical load. The battery charging system includes the battery pack mounted in the vehicle, the vehicle-mounted electrical load that can be driven by a current from the battery pack, and a battery charge controller that controls charging of the battery pack. When the battery pack is charged by using an external battery charger during operation of the load, the battery charge controller requires the external battery charger to supply a sum current that is a sum of a current for charging the battery pack and a current for driving the load to the vehicle.

Abstract: A storage battery has at least battery banks, switching units, a charging terminal, a discharging terminal and a battery management unit. The battery banks form a bank structure. Each switching unit electrically connects a group of the battery banks with either the charging terminal or the discharging terminal, and disconnects the group of the battery banks from the charging terminal or the discharging terminal. The battery management unit instructs the switching units to electrically and simultaneously connect one or more battery banks to the charging terminal during charging, and to electrically and simultaneously connect one or more battery banks to the discharging terminal during discharging.

Abstract: A pair of pressure plates and a spring unit situated between the pair of pressure plates. The spring unit includes plural springs. Each spring includes, in a longitudinally sectional shape, a curved central portion having substantially arc shape projecting in a direction perpendicular to an expansion/contraction direction, a pair of curved end portions each having substantially arc shape projecting at extensions of both ends of the curved central portion in a direction opposite to the projecting direction of the curved central portion, and base portions formed by extending edges of the curved end portions in substantially parallel with the direction perpendicular to the expansion/contraction direction. The base portions are respectively secured to the pair of pressure plates so the spring is located between the pair of pressure plates. The spring length in natural state has linear straight portions between the curved central portion and the curved end portions.