Hitachi Maxell, Limited

Hitachi Microcomputer System, Ltd.

Eiji Matsumasa

Takeshi Yamaguchi

Hiroshi Maruyama

Shinji Tanaka

Takehisa Yokohama

Hideaki Ebihara

Kouichi Horisaki

Yosifumi Sakaguchi

A battery package including a battery having at least one flat mount face defined therein, an electric circuit device for controlling discharging and charging of the battery, and a generally plate-like protective member mounted on the battery so as to cover the electric circuit device. The electric circuit device is made up of a plurality of circuit component parts and is mounted on the flat mount face with the circuit component parts held in tight contact with the flat mount face. The protective member includes an oblong plate member and side flanges protruding transversely from opposite side edges of the plate member to define a cavity. In an assembled condition with the protective member fitted to the battery, the electric component parts are accommodated within the cavity.

Battery package

A protection circuit device for protecting a secondary battery from an overcharge and/or an overdischarge has first and second terminals, across which a charger and a load are alternatively connectable. A first switch and/or a second switch may be provided in series with the secondary battery between the first and second terminals. In a charging operation mode, the second switch is kept conductive. A charging operation is performed with the first switch made conductive. When the battery is overcharged for some reasons, the first switch is turned off. Upon connection of a load across the first and second terminals, the first switch is restored to a conductive state for a discharging operation which releases the battery from an overdischarge state. In a discharging operation mode, the first switch is kept conductive. A discharge operation is performed with the second switch made conductive. When the battery is overdischarged, the second switch is caused to remain conductive even after commencement of the overdischarge, so that the battery can continue the discharge operation if the temporary overdischarge does not last longer than the predetermined period of time.

Secondary battery protection device from overcharge/overdischarge

Growing community of inventors

Kyoto, Japan

Eiji Matsumasa