Battery-state monitoring system for a battery group

• US 6,252,376 B1
• Filed: 03/16/1999
• Issued: 06/26/2001
• Est. Priority Date: 03/17/1998
• Status: Expired due to Fees

• Current Assignee: Japan Storage Battery Company Limited (GS Yuasa Corporation)
• Original Assignee: Japan Storage Battery Company Limited (GS Yuasa Corporation)
• Inventors: Ueda, Kiyoshi, Nakamura, Hideji
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/268,655
• Time in Patent Office: 833 Days
• Field of Search: 320/132, 320/136, 324/426
• US Class Current: 320/132
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: G01R 31/006 on road vehicles, e.g. automobiles or trucks testing of ignition installations peculiar to internal combustion engines F02P17/00
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

A plurality of battery modules are provided for each module monitoring unit. When a battery module is normal, a photo-FET of a photocoupler contained in a module monitoring unit 5 associated with the battery module is turned on. When it is abnormal, the photo-FET is turned off. Those photo-FETs, provided in association with the battery modules, are connected in series by two signal lines. A management unit detects whether the circuit including those signal lines is opened or closed, and finds an abnormal battery module on the basis of the detection.

Claims

1. A battery-state monitoring system for a battery group comprising:

a plurality of battery module monitoring units each comprising;

battery-state detecting means for detecting at least one state of each of plural battery modules forming a battery group;

a switching element which turns on when the state of said battery module, detected by said battery-state detecting means, is a predetermined state, and turns off when said state is a state different from said predetermined state; and

current detecting means connected in series or parallel to said switching element;

two signal lines connecting said switching elements of said plurality of module monitoring units in series; and

a management unit comprising first means for supplying pulse current to said two signal lines; and

a second means for detecting as to whether the circuit including said two signal lines is opened or closed, said management unit judging the states of said plurality of battery modules by the result of the detecting operation by said second means.

2. A battery-state monitoring system for a battery group according to claim 1, wherein each said battery module monitoring unit is driven or selects a time to turn on or off said switching element by current, directed in a direction, fed from a pulse current source provided in said management unit, and sends the state of said battery module to said management unit by interrupting or allowing a flow of a current of which the direction is opposite to said direction by turning on or off said switching element.

3. The battery-state monitoring system for a battery group according to claim 1, wherein said plurality of battery module monitoring units receive a signal defined a sequence of current pulses of a direction, derived from said pulse current source provided in said management unit, said switching element of only said battery module monitoring unit specified by said signal defined by the sequence of current pulses is turned on or off, and said management unit communicates with said specified module monitoring unit by use of the current of which the direction is opposite to that of said sequence of current pulses.

4. The battery-state monitoring system for a battery group according to claim 1, wherein each said battery module monitoring unit further comprises comparing means for comparing a numerical value based on the state of said battery module detected by said battery-state detecting means with a predetermined numerical value, and a switching operation of said switching element is controlled on the basis of the result of the comparing operation by said comparing means.

5. The battery-state monitoring system for a battery group according to claim 1, further comprising mode select means for selecting a sleep mode to reduce power consumption by making invalid most of the functions of said battery module monitoring unit, or a normal mode to allow said battery module monitoring units to normally operate, said mode select means changing the operation mode of said battery module monitoring unit from the sleep mode to the normal mode in response to a start-up signal from said management unit.

6. The battery-state monitoring system for a battery group according to claim 1, wherein said switching element is of the normal-on type, and turned on when receiving no control signal, and turned off when receiving a control signal.

7. The battery-state monitoring system for a battery group according to claim 1, wherein said battery module monitoring units time sequentially turn on or off said switching elements at predetermined time intervals in accordance with states representative of a plurality of characteristics of each said battery module.

8. A battery-state monitoring system for a battery group comprising:

a plurality of battery module monitoring units each comprising;

battery-state detecting means for detecting at least one state of each of plural battery modules forming a battery group;

a switching element which turns on when the state of said battery module, detected by said battery-state detecting means, is a predetermined state, and turns off when said state is a state different from said predetermined state; and

current detecting means connected in series or parallel to said switching element;

two signal lines connecting said switching elements of said plurality of module monitoring units in series; and

a management unit comprising first means for supplying a pulse current directed in a direction and a pulse current directed in an opposite direction to said two signal lines; and

a second means for detecting as to whether the circuit including said two signal lines is opened or closed, said management unit judging the states of said plurality of battery modules by the result of the detecting operation by said second means.