Ntt Facilities, Inc.

Hiroshi Wakaki

Toshio Matsushima

Nobuhiko Susuki

A remaining-battery-capacity estimating apparatus estimates the remaining capacity of a battery used as a backup. The apparatus reduces the voltage output from a rectifier to an actual load, measures current flowing from the rectifier and the battery to the actual load and a dummy load device provided separately from the actual load, controls the load of the dummy load device such that the measured current is a predetermined value, and calculates the remaining capacity of the battery based on the terminal voltage of the battery and the discharging time of discharging the battery to the actual load and the dummy load device, by referring to battery data indicating the relationship among the discharging time of the battery, the terminal voltage of the battery, and the remaining capacity of the battery, at a predetermined current of the battery.

Remaining-battery-capacity estimating apparatus, remaining-battery-capacity estimating method, and remaining-battery-capacity estimating computer program

A secondary-battery management apparatus calculates the possible discharge duration of a secondary battery correctly even after a load current changes. The secondary-battery management apparatus calculates the remaining capacity and the remaining lifetime of the secondary battery in accordance with a measured temperature of the battery in a standby state, calculates the remaining capacity of the battery in accordance with a measured discharging current of the battery while the battery is in a discharging state, and calculates the remaining capacity of the battery in accordance with a measured charging current while the battery is in a charging state. When discharging from the battery is required by means of a reduction of an output voltage of a rectifier, the deterioration of the battery is checked by discharging to a load device. A battery capacity is checked by measuring the discharge duration of the battery in the discharge by the load current pattern.

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Tokyo, Japan

Hiroshi Wakaki