Japan Storage Battery Co., Ltd.

Mitsubishi Denki Kabushiki Kaisha

Hideji Nakamura

Kiyoharu Anzai

Daisuke Konishi

Yoshihiko Mizuta

Toshiaki Hayashi

Motoshi Kiribayashi

Kiyoshi Ueda

Shinji Fujihara

Makoto Wanezaki

In order to provide a battery charging state arithmetic operation device which can judge a charging state of a battery currently being used easily and in a short time, there are provided battery voltage calculation meanswith specified load for calculating a first and a second battery voltages when a battery current is at a specified load current value from a first I-V characteristic of the battery which is in a first state as a currently used state and is stored in first I-V characteristic storage meansand a second I-V characteristic which is in a second state where the amount of remaining energy is small and is stored in second I-V characteristic storage means, and SOC arithmetic operation meansfor calculating an SOC (charging state) of the battery in the first state by using the first and the second battery voltages calculated.

Battery charging state arithmetic operation device for calculating charging state of battery, and battery charging state arithmetic operation method

A plurality of battery modules are provided for each module monitoring unit. When a battery module is normal, a photo-FET of a photocoupler contained in a module monitoring unit,associated with the battery module is turned on. When it is abnormal, the photo-FET is turned off. Those photo-FETs, provided in association with the battery modules, are connected in series by two signal lines. A management unit detects whether the circuit including those signal lines is opened or closed, and finds an abnormal battery module on the basis of the detection.

Battery-state monitoring system for a battery group

Forced discharging circuits each of which is configured by connecting in series a transistor, a reverse blocking Zener diode, and a discharging resistor are connected between positive and negative output terminals of cells, respectively. In each of the Zener diodes, the Zener voltage is set to be substantially equal to the cut-off voltage of discharge of the corresponding cell. The bases of the transistors are connected to a switching control circuit. The transistor of each of the forced discharging circuits is set so as to have a larger on-duty ratio, as the cell to which the forced discharging circuit is connected is remoter from a ground line, so that the average currents flowing through the cells are equal to one another.

Capacity leveling circuit for a battery group

Growing community of inventors

Kyoto, Japan

Hideji Nakamura