# US 11,079,439 B2 · Protection circuit for battery monitoring device, and battery monitoring device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,079,439 B2
- Document ID: US11079439B2
- Status: Granted
- Kind: B2
- Application number: 16/467,344
- Filed: 2017-11-16
- Published: 2019-10-24
- Granted: 2021-08-03
- Earliest claimed: 2016-12-07
- Assignees: Autonetworks Technologies, Ltd.; Sumitomo Wiring Systems, Ltd.; Sumitomo Electric Industries, Ltd.
- Applicants: AutoNetworks Technologies, Ltd.; Sumitomo Wiring Systems, Ltd.; Sumitomo Electric Industries, Ltd.
- Inventors: Shinichiro Sato
- Web page: https://patentgrep.com/patent/US11079439B2

## CPC

- G01R 1/36: Overload-protection arrangements or circuits for electric measuring instruments
- G01R 31/382: Arrangements for monitoring battery or accumulator variables, e.g. SoC
- G01R 31/3835: involving only voltage measurements
- H01M 10/48: Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569)
- H01M 10/482: {for several batteries or cells simultaneously or sequentially}
- H02H 9/045: {adapted to a particular application and not provided for elsewhere}
- H02J 7/50: acting upon multiple batteries simultaneously or sequentially
- H02J 7/80: including monitoring or indicating arrangements
- G01R 31/396: Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
- H01M 2200/00: Safety devices for primary or secondary batteries
- H01M 2220/20: Batteries in motive systems, e.g. vehicle, ship, plane
- Y02E 60/10: Energy storage using batteries
- Y02T 10/70: Energy storage systems for electromobility, e.g. batteries
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H)
- H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

In a protection circuit, a signal line group includes a plurality of voltage signal lines, and the voltage signal lines are connected to electrode portions of a plurality of unit batteries or electrode portions of a battery module. A first protection circuit portion includes a plurality of Zener diodes, and the Zener diodes are connected in parallel to the unit batteries between the plurality of voltage signal lines. A resistor portion group includes a plurality of resistor portions, and the resistor portions are interposed between the Zener diodes and the unit batteries on the voltage signal lines and restrict a current. A second protection circuit portion includes a plurality of varistors, and the varistors are connected in parallel to the unit batteries between the plurality of voltage signal lines.

## Claims

### Claim 1

A protection circuit for a battery monitoring device that monitors a battery module having a configuration in which a plurality of unit batteries are connected to each other in series, the protection circuit comprising:
a signal line group including a plurality of voltage signal lines, which are electrically connected to inter-battery electrode portions between the plurality of unit batteries that are connected to each other in series, or electrode portions at end portions of the battery module;
a first protection circuit portion including a plurality of Zener diodes that are connected to each other in series, the Zener diodes being connected in parallel to the unit batteries between the plurality of voltage signal lines, an anode of each of the Zener diodes being connected to one of the voltage signal lines on a negative electrode side of a corresponding one of the unit batteries that is connected in parallel to the Zener diode, and a cathode being connected to one of the voltage signal lines on a positive electrode side;
a resistor portion group including a plurality of resistor portions for restricting a current, the resistor portions being interposed between the Zener diodes and the unit batteries on the respective voltage signal lines; and
a second protection circuit portion including a plurality of varistors that are connected to each other in series, the varistors being connected in parallel to the unit batteries between the plurality of voltage signal lines, and terminals of the varistors being connected to the voltage signal lines between the resistor portions and the unit batteries,
wherein if an overvoltage occurs at both ends of the battery module when an open fault has occurred in some of the plurality of unit batteries, a current flows through the varistor and the Zener diode that are arranged in series with respect to the unit battery in which the open fault has occurred.

### Claim 2 (depends on 1)

A battery monitoring device comprising:
the protection circuit according to claim 1; and
a monitoring circuit connected to the plurality of voltage signal lines in the protection circuit, a voltage applied to the voltage signal lines being input to the monitoring circuit.