Monitoring battery cell voltage

• US 20080012570A1
• Filed: 08/15/2007
• Published: 01/17/2008
• Est. Priority Date: 07/17/2006
• Status: Abandoned Application

• Current Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Original Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Inventors: Bucur, Constantin
• Application Number:
  US11/893,155
• Publication Number:
  US 20080012570A1
• Time in Patent Office: Days
• US Class Current: 324/426
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• 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: 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 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2250/30 Fuel cells in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 8/04365 of other components of a fuel cell or fuel cell stacks
• CPC Class Codes: H01M 8/04552 of the individual fuel cell
• CPC Class Codes: H01M 8/04671 of the individual fuel cell
• 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: H02J 7/005 Detection of state of health [SOH]
• CPC Class Codes: Y02B 90/10 Applications of fuel cells in buildings
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A battery monitoring circuitry is provided. The battery monitoring circuitry includes a plurality of voltage detection paths and a logic device. Each voltage detection path is coupled to a battery cell and is operable for comparing a cell voltage of the battery cell with a switch threshold of a switch. Each voltage detection path is ON if the cell voltage is greater than the switch threshold. The logic device is coupled to the plurality of voltage detection paths and is operable for generating an alert signal according to a conductance status of each voltage detection path.

Claims

1. A monitoring circuit comprising:

a plurality of voltage detection paths, wherein each voltage detection path of said plurality of voltage detection paths is coupled to a battery cell and is operable for comparing a cell voltage of said battery cell with a switch threshold of a switch, and wherein each voltage detection path is ON if said cell voltage is greater than said switch threshold; and

a logic device coupled to said plurality of voltage detection paths operable for generating an alert signal according to a conductance status of each voltage detection path.

2. The monitoring circuit of claim 1, wherein said switch comprises a transistor.

3. The monitoring circuit of claim 2, wherein said switch threshold comprises a transistor threshold of said transistor.

4. The monitoring circuit of claim 1, wherein said switch comprises a diode.

5. The monitoring circuit of claim 4, wherein said switch threshold comprises a diode threshold of said diode.

6. The monitoring circuit of claim 1, wherein said switch comprises a diode and a transistor.

7. The monitoring circuit of claim 6, wherein said switch threshold comprises a summation of a diode threshold of said diode and a transistor threshold of said transistor.

8. The monitoring circuit of claim 1, wherein each voltage detection path comprises a resistor coupled to said switch.

9. The monitoring circuit of claim 1, wherein each voltage detection path generates a detection signal according to said conductance status, which is received by said logic device.

10. Agas gauge circuitry comprising:

a plurality of voltage detection paths, wherein each voltage detection path of said plurality of voltage detection paths is coupled to a battery cell and is operable for comparing a cell voltage of said battery cell with a switch threshold of a switch, and wherein each voltage detection path is ON if said cell voltage is greater than said switch threshold;

a logic device coupled to said plurality of voltage detection paths operable for generating an alert signal according to a conductance status of each voltage detection path; and

a controller coupled to said logic device operable for receiving said alert signal, and for halting power delivery to a load if at least one of the plurality of voltage paths is OFF.

11. The gas gauge circuitry of claim 10, wherein said switch comprises a transistor.

12. The gas gauge circuitry of claim 11, wherein said switch threshold comprises a transistor threshold of said transistor.

13. The gas gauge circuitry of claim 10, wherein said switch comprises a diode.

14. The gas gauge circuitry of claim 13, wherein said switch threshold comprises a diode threshold of said diode.

15. The gas gauge circuitry of claim 10, wherein said switch comprises a diode and a transistor.

16. The gas gauge circuitry of claim 15, wherein said switch threshold comprises a summation of a diode threshold of said diode and a transistor threshold of said transistor.

17. The gas gauge circuitry of claim 10, wherein each voltage detection path comprises a resistor coupled to said switch.

18. The gas gauge circuitry of claim 10, wherein each voltage detection path generates a detection signal according to said conductance status, which is received by said logic device.

19. The gas gauge circuitry of claim 10, further comprising:

a plurality of registers, wherein each register of said plurality of registers is coupled to each voltage detection path and is operable for storing data which indicates said conductance status.

20. The gas gauge circuitry of claim 19, wherein said controller accesses said plurality of registers to identify an off voltage detection path of said plurality of voltage detection paths.

21. A method of monitoring cell voltages, comprising:

comparing a battery cell voltage for each battery cell of a plurality of battery cells with a switch threshold of a switch;

turing on said switch if said battery cell voltage is greater than said switch threshold;

generating a detection signal for each battery cell according to a conductance status of said switch, wherein said detection signal indicates whether said battery cell voltage is greater than said switch threshold.

22. The method of claim 21 further comprising:

generating an alert signal according to said detection signal.

23. The method of claim 21, wherein said switch comprises a transistor.

24. The method of claim 23, wherein said switch threshold comprises a transistor threshold of said transistor.

25. The method of claim 21, wherein said switch comprises a diode.

26. The method of claim 25, wherein said switch threshold comprises a diode threshold of said diode.