Hitachi Chemical Company, Ltd.

Hitachi-Johnson Controls Air Conditioning, Inc.

Keisuke Fukuhara

Masahiro Watanabe

Hideki Inoue

Keiko Abe

Toshiyuki Sawa

Ichiro Shimoura

Hisaaki Takabayashi

Tomohiro Kato

Akitoshi Kawazoe

Kazuma Hosokawa

Hisashi Daisaka

Kosuke Ohnishi

Jiaye Cai

This invention reduces degradation of respective lead storage batteries making up a lead storage battery bank and extends the longevity of the lead storage batteries. A lead storage battery system includes an individual battery state measurement unitthat measures current, voltage, temperature etc. of individual lead storage batteriesor lead storage battery modulesmaking up a lead storage battery bank, a state-of-charge model storage unitthat accumulates state-of-charge models representing a correlation between the battery states and a state of charge, a state-of-charge estimation unitthat estimates individual states of charge of the respective lead storage batteriesor lead storage battery modulesfrom the state-of-charge models and the battery states, a state-of-charge variation range determination unitthat calculates a state-of-charge maximum value and a state-of-charge minimum value, and an equalization-charging management unitthat controls performance of an equalization charge on the lead storage battery bank. The equalization-charging management unitperforms the equalization charge so that the state-of-charge maximum value falls within a range lower than an overcharge region and the state-of-charge minimum value falls within a range higher than a sulfation region.

Lead storage battery system

Growing community of inventors

Tokyo, Japan

Keisuke Fukuhara