Capacity leveling circuit for a battery group

• US 6,191,555 B1
• Filed: 03/29/2000
• Issued: 02/20/2001
• Est. Priority Date: 03/29/1999
• Status: Expired due to Fees

• Current Assignee: GS Yuasa Corporation
• Original Assignee: Japan Storage Battery Company Limited (GS Yuasa Corporation)
• Inventors: Konishi, Daisuke, Mizuta, Yoshihiko
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/538,287
• Time in Patent Office: 328 Days
• Field of Search: 320/110, 320/112, 320/116, 320/117, 320/118, 320/119, 320/121, 320/132
• US Class Current: 320/118
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Voltage dividing circuits P1 to P3 are connected between the GND line connected to a battery B and the positive terminals of cells C1 to C3, respectively. Correcting discharging circuits D1 to D3 are connected between an output line on the side of the positive terminal of the battery B and the positive terminals of the cells C1 to C3, respectively. The amounts of discharges of the cells due to the correcting discharging circuits D1 to D3 are set to be equal to those of the cells due to the voltage dividing circuits P1 to P3, respectively, thereby leveling the capacities of the cells.

Claims

1. A capacity leveling circuit for a battery group comprising:

a battery group formed of a plurality of cells in series;

voltage dividing circuits connected between one of output terminals of said battery group and output terminals on one side of said cells; and

,

correcting discharging circuits connected between another output terminal of said battery group and said one output terminal of each of said cells, one output terminal of each of said cells being connected to voltage dividing circuits;

wherein amounts of discharges of each of said cells in said correcting discharging circuits are set to be equal to amounts of discharges of each of cells in said voltage dividing circuits.

2. The capacity leveling circuit for a battery group according to claim 1, wherein

said voltage dividing circuit comprising:

at least one first switch element; and

,

at least one resistor;

wherein, said voltage dividing circuit is configured by connecting said first switch element and said resistor;

said correcting discharging circuit comprising;

at least one second switch element; and

at least one resistor;

wherein, said correcting discharging circuit is configured by connecting said second switch element and said resistor.

3. The capacity leveling circuit for a battery group according to claim 2, wherein, said first and second switch elements are photo FETs.

4. The capacity leveling circuit for a battery group according to claim 2, wherein,

terminal portions of all said correcting discharging circuits, said terminal portions being commonly connected to the other output terminal of said battery group, are formed as a single common line,

said common line has said second FET, said second FET being commonly used by all said correcting discharging circuits,

said correcting discharging circuits comprising a diode, said diode being disposed in a of each of said discharging circuits except said common line with blocking a current in a direction opposite to a current direction in a case of a turn-on of said second switch element, from flowing through said resistor of said correcting discharging circuit.

5. The capacity leveling circuit for a battery group according to claims 1, wherein a ratio of a resistance of each of said voltage dividing circuits to a resistance of each of said correcting discharging circuits is equal to a ratio of a number of cells of said voltage dividing circuit to a number of cells of said correcting discharging circuit.

6. The capacity leveling circuit for a battery group according to claims 2, wherein turn-on periods of said first switch elements of all said voltage dividing circuits coincide with one another.

7. The capacity leveling circuit for a battery group according to claims 2, said second switch element is disposed in each of said correcting discharging circuits, respectively.

8. A method of leveling a capacity of a battery group, comprising a step of:

in voltage dividing circuits being connected between one of output terminals of said battery group and output terminals on one side of cells, measuring voltages of said cells respectively;

in correcting discharging circuit being connected between another output terminal of said battery group and said one output terminal of each of said cells, one of said voltage dividing circuits being connected to said one output terminal, said cells being not connected to said one voltage dividing circuit in series, discharging said cells; and

,

setting the amounts of discharges of said cells in said correcting discharging circuits, and those of each of said cells in said voltage dividing circuits to be equal to one another.

9. The method of leveling a capacity of a battery group according to claim 8, wherein said voltage dividing circuit comprising:

at least one first switch element; and

,

at least one resistor;

wherein, said voltage dividing circuit is configured by connecting said first switch element and said resistor;

said correcting discharging circuit comprising;

at least one second switch element; and

at least one resistor;

wherein, said correcting discharging circuit is configured by connecting said second switch element and said resistor.

10. The method of leveling a capacity of a battery group according to claim 8, wherein, said first and second switch elements are photo FETs.

11. The method of leveling a capacity of a battery group according to claims 9, wherein turn-on periods of said first switch elements of all said voltage dividing circuits coincide with one another.

12. The method of leveling a capacity of a battery group according to claims 9, said second switch element is disposed in each of said correcting discharging circuits, respectively.