Mitsumi Electric Company Ltd.

Iwao Kitamura

Daisuke Kimura

Koichi Yamaguchi

Yoshihiro Motoichi

Tsutomu Yamauchi

Hirotaka Kataya

A control system includes a secondary battery protection apparatus and a device. The secondary battery protection apparatus includes one or more monitoring terminals each provided in a path different from power paths, each monitoring terminal being operable for monitoring a potential at a negative electrode of a given secondary battery cell among a plurality of the secondary battery cells. The secondary battery protection apparatus includes one or more internal switches each of which is provided in an internal line between the negative electrode of a given secondary battery cell and a given monitoring terminal. The device includes a balance control circuit that adjusts, based on potentials monitored by the monitoring terminals, a current flowing into a line path that includes a corresponding internal line. The balance control circuit controls balance among the cell voltages for the secondary battery cells, based on the adjusted current.

Control system, control method and integrated circuit for secondary battery protection

A secondary battery protection circuit for protecting a secondary battery with multiple connected-in-parallel cells, includes a charging fault detection unit for each cell for prohibiting charging of the corresponding cell when overcharging and/or charging over-current for the corresponding cell is detected; a charging control element for each cell for cutting off a charging path for the corresponding cell when the charging of the corresponding cell is prohibited; a detection resistor for each cell inserted in series in the charging path; and a balance control unit for, in order to balance a first charging current flowing in a first charging path for a first cell with a second charging current flowing in a second charging path for a second cell, controlling a difference between the first and second charging currents in a saturation region of the charging control element based on a detection voltage generated by the detection resistor.

Secondary battery protection circuit for causing a desired current to flow in each of the cells, secondary battery protection integrated circuit, and battery pack

A secondary battery protecting integrated circuit protects a secondary battery by controlling a switch circuit inserted in series on a path connected to a first electrode of the secondary battery. The secondary battery protecting integrated circuit includes: a sense terminal connected to a monitor terminal provided so that a first electric potential of the first electrode is monitorable; a first power supply terminal connected to the path; a second power supply terminal connected to a second electrode of the secondary battery; an internal wiring line configured to connect the first power supply terminal and the sense terminal; an internal switch on the internal wiring line; an abnormality detecting circuit configured to detect a predetermined abnormality; and a switch control circuit configured to turn on the internal switch when the predetermined abnormality is not detected, and configured to turn off the internal switch when the predetermined abnormality is detected.

Secondary battery protecting integrated circuit, secondary battery protecting circuit, charge control circuit, and battery pack

A charging control circuit for a secondary battery includes a temperature detection terminal for detecting the temperature of a secondary battery from an input detected voltage; a temperature comparison part having four threshold voltages corresponding to four reference temperatures, the temperature comparison part being configured to compare the four threshold voltages with the detected voltage input to the temperature detection terminal and to output a temperature range signal indicating the temperature range of the detected voltage; and a control part configured to control a charging current and/or a charging voltage based on the temperature range signal output from the temperature comparison part.

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Tokyo, Japan

Iwao Kitamura