Battery systems with embedded cell monitors

• US 20080129522A1
• Filed: 11/30/2007
• Published: 06/05/2008
• Est. Priority Date: 12/01/2006
• Status: Active Grant

• Current Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Original Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Inventors: Keim, James, Popescu, Serban-Mihai, Densham, Bill
• Granted Patent: US 7,755,500 B2
• Time in Patent Office: Days
• US Class Current: 340/636.15
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery pack is disclosed. The battery pack includes a battery cell and a cell monitor. The cell monitor is embedded in the battery cell and is operable for monitoring the battery cell and for generating an alert signal indicative of a predetermined condition of the battery cell.

Claims

1. A battery pack comprising:

a battery cell; and

a cell monitor embedded in said battery cell and operable for monitoring said battery cell and for generating an alert signal indicative of a predetermined condition of said battery cell.

2. The battery pack of claim 1, wherein said cell monitor comprises a temperature sensor operable for monitoring a temperature of said battery cell, and wherein said cell monitor generates said alert signal if said temperature of said battery cell is greater than a predetermined threshold.

3. The battery pack of claim 1, wherein said cell monitor comprises a voltage sensor operable for monitoring a voltage of said battery cell, and wherein said cell monitor generates said alert signal if said voltage of said battery cell is greater than a predetermined threshold.

4. The battery pack of claim 1, wherein said cell monitor comprises:

a sensing circuit operable for detecting said predetermined condition of said battery cell and for generating a detecting signal; and

a transmitter operable for receiving said detecting signal and for generating said alert signal according to said detecting signal from said sensing circuit.

5. The battery pack of claim 4, wherein said transmitter comprises:

a pulse generator operable for receiving said detecting signal and for generating a plurality of pulses according to said detecting signal; and

a switch coupled to said pulse generator and operable for receiving said plurality of pulses and for generating said alert signal.

6. The battery pack of claim 4, wherein said transmitter comprises:

an oscillator operable for receiving said detecting signal and for generating said alert signal according to said detecting signal; and

a capacitor coupled to said oscillator and operable for transferring said alert signal to said battery cell.

7. The battery pack of claim 1, further comprising:

a receiver coupled to a positive terminal and a negative terminal of said batter pack and operable for receiving said alert signal and for generating a driving signal according to said alert signal; and

a battery management unit operable for receiving said driving signal from said receiver and for generating a switching signal according to said driving signal, wherein said switching signal triggers a protection action for said battery pack.

8. The battery -pack of claim 7, wherein said receiver comprises a high-pass filter.

9. The battery pack of claim 7, wherein said receiver comprises a band-pass filter.

10. The battery pack of claim 7, wherein said battery management unit comprises:

a rectifier for receiving said driving signal and for generating a voltage signal; and

a comparator for comparing said voltage signal with a reference signal, wherein said switching signal is generated according to a result of said comparison.

11. An electronic system comprising:

a load; and

a battery pack operable for supplying power to said load, wherein said battery pack comprises;

a battery cell; and

a cell monitor embedded in said battery cell, and operable for monitoring said battery cell and for generating an alert signal indicative of a predetermined condition of said battery cell.

12. The electronic system of claim 11, wherein said cell monitor comprises a temperature sensor operable for monitoring a temperature of said battery cell, and wherein said cell monitor generates said alert signal if said temperature of said battery cell is greater than a predetermined threshold.

13. The electronic system of claim 11, wherein said cell monitor comprises a voltage sensor operable for monitoring a voltage of said battery cell, and wherein said cell monitor generates said alert signal if said voltage of said battery cell is greater than a predetermined threshold.

14. The electronic system of claim 11, wherein said cell monitor comprises:

a sensing circuit operable for detecting said predetermined condition of said battery cell and for generating a detecting signal; and

a transmitter operable for receiving said detecting signal and for generating said alert signal according to said detecting signal from said sensing circuit.

15. The electronic system of claim 14, wherein said transmitter comprises:

a pulse generator operable for receiving said detecting signal and for generating a plurality of pulses according to said detecting signal; and

a switch coupled to said pulse generator and operable for receiving said plurality of pulses and for generating said alert signal.

16. The electronic system of claim 14, wherein said transmitter comprises:

an oscillator operable for receiving said detecting signal and for generating said alert signal according to said detecting signal; and

a capacitor coupled to said oscillator and operable for transferring said alert signal to said battery cell.

17. The electronic system of claim 11, further comprising:

a receiver coupled to a positive terminal and a negative terminal of said batter pack and operable for receiving said alert signal and for generating a driving signal according to said alert signal; and

a battery management unit operable for receiving said driving signal and for generating a switching signal according to said driving signal, wherein said switching signal triggers a protection action for said battery pack.

18. The electronic system of claim 17, wherein said battery management unit comprises:

a rectifier for receiving said driving signal and for generating a voltage signal; and

a comparator for comparing said voltage signal with a reference signal.

19. The electronic system of claim 11, where said load comprises a vehicle motor.

20. The electronic system of claim 11, wherein said load comprises a computer system.

21. A method for monitoring a battery pack, comprising:

monitoring a battery cell in said battery pack by a cell monitor which is embedded in said battery cell; and

generating an alert signal indicative of a predetermined condition of said battery cell.

22. The method of claim 21, comprising:

monitoring a temperature of said battery cell; and

generating said alert signal if said temperature of said battery cell is greater than a predetermined threshold.

23. The method of claim 21, comprising:

monitoring a voltage of said battery cell; and

generating said alert signal if said voltage of said battery cell is greater than a predetermined threshold.

24. The method of claim 21, comprising:

triggering a protection action for said battery pack according to said alert signal.