Battery pack

• US 6,420,852 B1
• Filed: 08/19/1999
• Issued: 07/16/2002
• Est. Priority Date: 08/21/1998
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Sato, Bunya
• Primary Examiner(s): Han, Jessica
• Assistant Examiner(s): TIBBITS, PIA FLORENCE
• Application Number:
  US09/377,373
• Publication Number:
  US 20020070707A1
• Time in Patent Office: 1,062 Days
• Field of Search: 320/116, 320/122, 320/132, 320/136, 320/134
• US Class Current: 320/134
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0024 Parallel/serial switching of connection of batteries to charge or load circuit
• CPC Class Codes: H02J 7/005 Detection of state of health [SOH]
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

When any one or ones of at least two cells connected in parallel together is judged to be faulty by a cell failure detector, it is electrically disconnected to the normal other cells. Alternatively, when any one or ones of at least two cells connected in series together is judged to be faulty by a controller, a cell current interrupter is shifted from a connected position to a disconnected position connected in series to the faulty cell to interrupt a current line while a cell short-circuit device connected in parallel to the faulty cell by the cell current interrupter is shifted from a disconnected position to a connected position, thereby shorting a circuit portion corresponding to the faulty cell.

Claims

1. A battery pack comprising:

a plurality of cells arranged in parallel to each other;

determining means for testing each cell in said plurality of cells by comparing the cell to a predetermined value of said cell to determine if the cell is faulty and outputting a signal indicating the faulty cell; and

disconnecting means for electrically disconnecting each faulty cell from the other cells in said plurality of cells based on said signal.

2. The battery pack of claim 1, wherein said determining means comprises:

current detecting means for detecting a current value of said battery pack and a current value of each cell of said plurality of cells; and

comparing means for receiving the detected current value of said battery pack and the detected current value of each cell of said plurality of cells from said current detecting means and comparing the detected current values with respective current reference values to determine which cell in said plurality of cells is faulty.

3. The battery pack of claim 1, wherein said disconnecting means contains an interrupting element to electrically disconnect each faulty cell from the other cells.

4. The battery pack of claim 3, wherein said interrupting element is not re-connectable once the faulty cell is electronically disconnected by said disconnecting means.

5. The battery pack of claim 3, wherein said interrupting element is re-connectable after the faulty cell is recovered from a failure.

6. A battery pack comprising:

a plurality of cell units;

a plurality of cells in each cell unit arranged in parallel to each other;

determining means for testing each cell in said plurality of cells to determine if the cell is faulty and outputting a signal indicating the faulty cell; and

disconnecting means for electrically disconnecting each faulty cell from the other cells in a cell unit based on said signal and for electrically disconnecting a number of cells of a respective cell unit equal to the number of faulty cells in said cell unit.

7. The battery pack of claim 6, wherein said determining means comprises:

current detecting means for detecting a current value of said battery pack and a current value of each cell of said plurality of cells; and

comparing means for receiving the detected current value of said battery pack and the detected current value of each cell of said plurality of cells from said current detecting means and comparing the detected current values with respective current reference values to determine which cell of said plurality of cells is faulty.

8. The battery pack of claim 6, wherein said disconnecting means contains an interrupting element to electrically disconnect each faulty cell from the other cells in said cell unit.

9. The battery pack of claim 8, wherein said interrupting element is not re-connectable once the faulty cell is electronically disconnected by said disconnecting means.

10. The battery pack of claim 8, wherein said current interrupting element is re-connectable after the faulty cell is recovered from a failure.

11. A battery pack comprising:

a plurality of cells arranged in series to each other;

determining means for testing each cell in said plurality of cells to determine if the cell is faulty; and

short circuiting means comprising;

first switching means arranged in series with each cell; and

second switching means arranged in parallel with each cell,

wherein said first switching means switches from a connected position to a disconnected position and said second switching means switches from a disconnected position to a connected position when said determining means determines a faulty cell.

12. The battery pack of claim 11, wherein the determining means comprises:

voltage detecting means for detecting a voltage of each cell; and

controlling means for comparing a difference between two detected voltage values detected by the voltage detecting means with a preset reference voltage in order to determine said faulty cell.

13. The battery pack of claim 11 wherein the determining means comprises:

voltage detecting means for detecting a voltage of each cell and a total voltage of said plurality of cells; and

controlling means for obtaining a value resulting from a division of the total voltage by the total number of cells in said battery pack, calculating a difference between the voltage of each cell and said value resulting from said division, and comparing said difference with a preset reference voltage in order to determine said faulty cell.

14. The battery pack of claim 11, wherein said first switching means is a non-resettable switching means.

15. The battery pack of claim 11, wherein said first switching means is a resettable switching means.

16. The battery pack of claim 11, wherein said second switching means is a non-resettable switching means.

17. The battery pack of claim 11, wherein said second switching means is a resettable switching means.