Hitachi Automotive Systems, Ltd.

Hitachi Astemo Ltd.

Akihiko Kudoh

Mutsumi Kikuchi

Tomonori Kanai

Hikaru Miura

Mitsuo Noda

Provided are a battery monitoring device capable of suppressing a current flowing to individual battery cells and enhancing the safety thereof, even when there is a short circuit, for example, in a connection line connecting substrates having integrated circuits mounted thereon and a substrate having a microcomputer mounted thereon or a connection line connecting the substrates having the integrated circuits mounted thereon, and a battery system using the same. Resistors are provided in a positive electrode input lineconnecting a positive electrode side of a battery pack groupand a total voltage detecting unitand/or a negative electrode input lineconnecting a negative electrode side of the battery pack groupand the total voltage detecting unitand the resistors of the positive electrode input lineand/or negative electrode input lineare arranged on individual cell monitoring circuit boardsand

Battery monitoring device and battery system using same

The present invention enables correct detection of the state of a relay provided on each of the positive and negative terminal sides of a secondary battery. A positive-side main relay makes or breaks continuity between first and second positive contact points, and a negative-side main relay makes or breaks continuity between first and second negative contact points. A microcomputer can measure a first voltage between the first positive and first negative contact points, a second voltage between the second positive and first negative contact points, and a third voltage between the first positive and second negative contact points. The microcomputer detects the state of the positive-side main relay based on a voltage measurement result obtained when the first and second voltages are measured synchronously, and detects the state of the negative-side main relay based on a voltage measurement result obtained when the first and third voltages are measured synchronously.

Battery monitor

A battery system includes a battery module having a plurality of assembled batteries. Battery monitoring circuits are provided to correspond to each of the assembled batteries of the battery module. A control circuit controls operation of the battery monitoring circuits. A first signal transmission path transmits signals that are input and output between the battery monitoring circuits and the control circuit. A first isolation element is connected to the control circuit, and a second isolation element is connected to the battery monitoring circuit. The first signal transmission path is isolated from the control circuit by the second isolation element. The electrical potential of the first signal transmission path is a floating potential in relation to the electrical potentials of the control circuit and battery monitoring circuits.

Battery system

A battery system includes a battery module having a plurality of assembled batteries. Battery monitoring circuits are provided to correspond to each of the assembled batteries of the battery module. A control circuit controls operation of the battery monitoring circuits. A first signal transmission path transmits signals that are input and output between the battery monitoring circuits and the control circuit. A first isolation element is connected to the control circuit, and a second isolation element is connected to the battery monitoring circuit. The first signal transmission path is isolated from the control circuit by the first isolation element and is isolated from the battery monitoring circuit by the second isolation element. The electrical potential of the first signal transmission path is a floating potential in relation to the electrical potentials of the control circuit and battery monitoring circuits.

A cell controller in a battery-monitoring device that monitors an assembled battery having a single cell group or a plurality of cell groups, each made up with a plurality of battery cells connected in series, includes: a startup terminal to which a first discharge resistor is connected and a startup voltage is applied; and a cell-balancing unit that executes cell balancing operation in order to adjust charge levels of the plurality of battery cells during a time period through which the startup voltage remains equal to or greater than a predetermined voltage, wherein: the startup voltage is applied for a predetermined length of time by a first timer unit that includes a passive element capable of accumulating electric energy and capable of discharging electric energy to the startup terminal.

Growing community of inventors

Hitachinaka, Japan

Akihiko Kudoh