Battery management system with signal transmission function

• US 8,237,405 B2
• Filed: 08/12/2011
• Issued: 08/07/2012
• Est. Priority Date: 01/06/2009
• Status: Active Grant

• Current Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Original Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Inventors: Li, Guoxing
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US13/209,282
• Publication Number:
  US 20110291618A1
• Time in Patent Office: 361 Days
• Field of Search: 320/103, 320/107, 320/114, 320/116, 320/117, 320/120, 320/122
• US Class Current: 320/116
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 3/0092 with use of redundant elements for safety purposes
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables
• 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: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• 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 battery management system can include a battery having a plurality of cells, a plurality of devices coupled to the battery, and a control unit coupled to a first device of the devices. The devices can assess the statuses of the cells. The control unit can communicate with a destination device of the devices via a default path and can communicate with the destination device via a backup path if an undesirable condition occurs in the default path.

Claims

1. A battery management system, comprising:

a control unit; and

a plurality of devices coupled to said control unit and configured for connection to a battery comprising a first battery pack and a second battery pack, said devices comprising a first device operable for assessing status of cells in said first battery pack and further comprising a second device operable for assessing status of cells in said second battery pack, wherein signal transmission between said first device and said second device is enabled using a common voltage shared by a cell in said first battery pack and a voltage regulator in said second device.

2. The system of claim 1, wherein said control unit is operable for communicating with said second device via a default path through said first device and via a backup path through said first device if an undesirable condition occurs in said default path.

3. The system of claim 1, wherein said signal transmission comprises status information for a cell in said second battery pack.

4. The system of claim 1, wherein said second device issues a signal for communication with said control unit when said second device is operating in master mode, said signal transmitted to said control unit through said first device.

5. The system of claim 1, wherein said control unit issues a signal for communication with said second device when said second device is operating in slave mode, said signal transmitted to said second device through said first device.

6. The system of claim 1, wherein said first device comprises a device powered by a cell that has the lowest voltage level among said cells.

7. The system of claim 1, wherein said second device comprises a device powered by a cell that has the highest voltage level among said cells.

8. A battery management system, comprising:

a plurality of devices coupled to a battery comprising a plurality of cells, said devices operable for assessing the statuses of said cells, wherein each of said devices comprises;

a monitoring block operable for outputting monitoring signals that indicate a status of a respective cell; and

a bus block coupled to said monitoring block and operable for transmitting said monitoring signals through a common voltage shared by an adjacent pair of said devices.

9. The system of claim 8, wherein said battery comprises a first battery pack and a second battery pack, and said plurality of devices comprise a first device operable for assessing status of cells in said first battery pack and further comprise a second device operable for assessing status of cells in said second battery pack, wherein said common voltage is provided by the positive terminal of a cell in said first battery pack and the output voltage of a voltage regulator in said second device.

10. The system of claim 8, further comprising a control unit coupled to a first device of said devices and operable for communicating with a destination device of said devices via a default path and for communicating with said destination device via a backup path if an undesirable condition occurs in said default path.

11. The system of claim 10, wherein said default path comprises a path via said control unit, an internal default signal path in said first device, a plurality of internal default signal paths inside a plurality of said devices and a plurality of external default signal paths between said first device and said destination device.

12. The system of claim 11, wherein said backup path comprises a path that is different from said default path in that, if said undesirable condition occurs in an external default signal path in said plurality of external default signal paths between said first device and said destination device, then said external default signal path is replaced by an external backup signal path that is located between said first device and said destination device.

13. The system of claim 10, wherein said backup path comprises a path that is different from said default path in that, if said undesirable condition occurs in an internal default signal path in said first device, then said internal default signal path in said first device is replaced by an internal backup signal path that is located in said first device.

14. The system of claim 10, wherein said control unit is further coupled to a second device of said devices, and wherein said backup path comprises a path via said control unit, an internal default signal path in said second device, a plurality of internal default signal paths inside a plurality of said devices and a plurality of external default signal paths between said second device and said destination device.

15. The system of claim 8, wherein said bus block comprises an internal signal path inside said bus block, wherein an external signal path outside said devices is coupled between said devices and is operable for transmitting said monitoring signals between said devices.

16. The system of claim 15, wherein said internal signal path comprises an internal default signal path and said external signal path comprises an external default signal path.

17. The system of claim 16, wherein said internal signal path further comprises an internal backup signal path and said external signal path further comprises an external backup signal path.

18. A method for enabling communication in a battery management system, said method comprising:

monitoring statuses of cells in a battery using a plurality of devices;

outputting monitoring signals that indicate said statuses; and

transmitting said monitoring signals between said devices and to a control unit using a common voltage shared by an adjacent pair of said devices.

19. The method of claim 18, further comprising:

determining if an undesirable condition occurs in a default path operable for enabling said communication between said control unit and a destination device; and

enabling said communication via a backup path if said undesirable condition is detected and otherwise enabling said communication via said default path.

20. The method of claim 18, wherein said battery comprises a first battery pack and a second battery pack, and said plurality of devices comprise a first device operable for assessing status of cells in said first battery pack and further comprise a second device operable for assessing status of cells in said second battery pack, wherein said common voltage is provided by the positive terminal of a cell in said first battery pack and the output voltage of a voltage regulator in said second device.