BATTERY PACK

• US 20020070707A1
• Filed: 08/19/1999
• Published: 06/13/2002
• Est. Priority Date: 08/21/1998
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: SATO, BUNYA
• Granted Patent: US 6,420,852 B1
• Time in Patent Office: Days
• 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 at least two cells connected in parallel to together, having:

means for judging individually the cells to detect whether they are normal or faulty;

a cell or cells, if any thus found faulty, being electrically disconnected from the normal other cells.

2. The battery pack as set forth in claim 1, wherein the cell failure detecting means comprises:

means for detecting a charging current in the whole battery pack;

means for detecting a charging current in each of the cells; and

a discriminator which is supplied with values of the detected charging currents from the total charging current detector and cell charging current detector and compares the detected charging currents with respective reference values to judge whether the cells are normal or faulty.

3. The battery pack as set forth in claim 1, further comprising a nonresettable type current interrupting element to electrically disconnect a one of the cells found faulty from the normal other cells.

4. The battery pack as set forth in claim 1, further comprising a resettable type current interrupting element to electrically disconnect a one of the cells found faulty from the normal other cells.

5. A battery pack comprising at least two series-connected cell units each consisting of at least two cells connected in parallel together, the battery pack having:

means for judging individually the cells to detect whether they are normal or faulty;

in the cell unit including a faulty cell or cells, the faulty cell being electrically disconnected from the normal other cells; and

in the cell unit including no faulty cell or cells, the normal cells as many as the faulty cells electrically disconnected from the normal other cells in the cell unit including the faulty cells, being electrically disconnected from the other cells.

6. The battery pack as set forth in claim 5, wherein the cell failure detecting means comprises:

means for detecting a charging current in the whole battery pack;

means for detecting a charging current in each of the cells; and

a discriminator which is supplied with values of the detected charging currents from the total charging current detector and cell charging current detector and compares the detected charging currents with respective reference values to judge whether the cells are normal or faulty.

7. The battery pack as set forth in claim 5, further comprising a nonresettable type current interrupting element to electrically disconnect a one of the cells found faulty from the normal other cells.

8. The battery pack as set forth in claim 5, further comprising a resettable type current interrupting element to electrically disconnect a one of the cells found faulty from the normal other cells.

9. A battery pack comprising at least two cells connected in series together, having:

means for judging individually the cells to detect whether they are normal or faulty; and

a cell short-circuiting means consisting of a first switching element connected in series to each of the cells, and a second switching element connected in parallel to each of the cells via a current interrupting element;

when the cell failure detecting means judges any one of the cells to be faulty, the first switching element in the cell short-circuiting means being shifted from a connected position to a disconnected position from each cell to interrupt a current line to each cell while the second switching element is shifted from a disconnected position to a connected position to short a circuit portion corresponding to a current line connected to the faulty cell.

10. The battery pack as set in claim 9, wherein the cell failure detecting means comprises:

means for detecting voltage of each of the cells; and

a controller in which a reference voltage is preset;

the controller being adapted to compare an absolute value of a difference between two voltage values detected by the cell voltage detectors with the reference voltage to judge whether the cells are normal or not.

11. The battery pack as set forth in claim 9, wherein the cell failure detecting means comprises:

means for detecting voltage of each of the cells;

means for detecting a total voltage of the plurality of cells; and

a controller in which a reference voltage is preset;

the controller being adapted to calculate a difference between a value resulted from division of a voltage value detected by the total voltage detecting means by the total number of the cells and a value detected by the cell voltage detector and compare an absolute value of the difference thus calculated with the reference voltage to judge whether the cells are normal or not.

12. The battery pack as set forth in claim 9, wherein the first switching element is of a non-resettable or resettable type.

13. The battery pack as set forth in claim 9, wherein the second switching element is of a non-resettable or resettable type.