Mode selection circuit for a battery, a method of selecting modes for the battery and a battery back-up power supply employing the circuit and method

• US 6,160,379 A
• Filed: 12/16/1999
• Issued: 12/12/2000
• Est. Priority Date: 10/15/1997
• Status: Expired due to Term

• Current Assignee: ABB Power Electronics Inc. (ABB Ltd.)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Thottuvelil, Vijayan Joseph, Chalasani, Subhas Chandra, Jacobs, Mark Elliot
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/465,509
• Time in Patent Office: 362 Days
• Field of Search: 320/127, 320/128, 320/130, 320/133, 320/119, 320/135, 320/140, 320/155
• US Class Current: 320/119
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/007194 of the battery

Abstract

For use with a reserve battery couplable to a charging circuit capable of providing a charging current to the reserve battery, a mode selection circuit and a method of operation thereof. The mode selection circuit includes, in one embodiment, (1) a signal generator that generates a signal based on a temperature of the reserve battery and (2) a mode-changing circuit, coupled to the signal generator, that accepts the signal and selects an alternative one of: (a) a non-charge mode in which the charging current is substantially interrupted when the temperature is greater than a reference temperature and (b) a charge mode in which the charging current is provided to the reserve battery when the temperature is less than the reference temperature.

Claims

1. For use with a reserve battery couplable to a charging circuit capable of providing a charging current to said reserve battery, a mode selection circuit, comprising:

a signal generator that generates a signal based on a time of day; and

a mode-changing circuit, coupled to said signal generator, that accepts said signal and selects an alternative one of;

a charge mode in which said charging current is provided to said reserve battery during a predetermined time of day, and

a non-charge mode in which said charging current is substantially interrupted during time periods other than said predetermined time of day.

2. The circuit as recited in claim 1 further comprising a charge detection circuit, coupled to said reserve battery, that monitors a charge of said reserve battery, said mode-changing circuit further selecting an alternative one of:

said charge mode in which said charging current is provided to said reserve battery during said predetermined time period and when said charge is below said predetermined value, and

said non-charge mode in which said charging current is substantially interrupted when said charge is above a predetermined value.

3. The circuit as recited in claim 1 wherein said charging circuit comprises an AC/DC rectifier.

4. The circuit as recited in claim 1 wherein said reserve battery is a valve-regulated lead acid (VRLA) battery.

5. The circuit as recited in claim 1 wherein said mode-changing circuit comprises a parallel-coupled switch and diode coupled to said reserve battery.

6. The circuit as recited in claim 1 wherein said mode-changing circuit comprises a low-voltage-disconnect (LVD) circuit coupled to said reserve battery.

7. The circuit as recited in claim 1 wherein said mode-changing circuit comprises a current control loop.

8. The circuit as recited in claim 1 wherein said signal generator comprises a clock.

9. For use with a reserve battery couplable to a charging circuit capable of providing a charging current to said reserve battery, a method of selecting modes for said reserve battery, comprising:

providing a signal based on a time of day with a signal generator; and

accepting said signal with a mode-changing circuit, coupled to said signal generator, and selecting an alternative one of;

a charge mode in which said charging current is provided to said reserve battery during a predetermined time of day, and

a non-charge mode in which said charging current is substantially interrupted during time periods other than said predetermined time of day.

10. The method as recited in claim 9 further comprising monitoring a charge of said reserve battery with a charge detection circuit, coupled to said reserve battery, that method further selecting an alternative one of:

said charge mode in which said charging current is provided to said reserve battery during said predetermined time period and when said charge is below said predetermined value, and

said non-charge mode in which said charging current is substantially interrupted when said charge is above a predetermined value.

11. The method as recited in claim 9 wherein said charging circuit comprises an AC/DC rectifier.

12. The method as recited in claim 9 wherein said reserve battery is a valve-regulated lead acid (VRLA) battery.

13. The method as recited in claim 9 wherein said mode-changing circuit comprises a parallel-coupled switch and diode coupled to said reserve battery.

14. The method as recited in claim 9 wherein said mode-changing circuit comprises a low-voltage-disconnect (LVD) circuit coupled to said reserve battery.

15. The method as recited in claim 9 wherein said mode-changing circuit comprises a current control loop.

16. The method as recited in claim 9 wherein said signal generator comprises a clock.

17. A battery back-up power supply, comprising:

a source of electrical power;

an AC/DC rectifier coupled to said source of electrical power;

a reserve battery couplable to a said AC/DC rectifier, said AC/DC rectifier capable of charging said reserve battery; and

a mode selection circuit, including;

a signal generator that generates a signal based on a time of day, and

a mode-changing circuit, coupled to said signal generator, that accepts said signal and selects an alternative one of;

a charge mode in which said charging current is provided to said reserve battery during a predetermined time of day, and

a non-charge mode in which said charging current is substantially interrupted during time periods other than said predetermined time of day.

18. The power supply as recited in claim 17 further comprising a charge detection circuit, coupled to said reserve battery, that monitors a charge of said reserve battery, said mode-changing circuit further selecting an alternative one of:

said charge mode in which said charging current is provided to said reserve battery during said predetermined time period and when said charge is below said predetermined value, and

said non-charge mode in which said charging current is substantially interrupted when said charge is above a predetermined value.

19. The power supply as recited in claim 17 wherein said reserve battery is a valve-regulated lead acid (VRLA) battery.

20. The power supply as recited in claim 17 wherein said mode-changing circuit comprises a parallel-coupled switch and diode coupled to said reserve battery.

21. The power supply as recited in claim 17 wherein said mode-changing circuit comprises a low-voltage-disconnect (LVD) circuit coupled to said reserve battery.

22. The power supply as recited in claim 17 wherein said mode-changing circuit comprises a current control loop.

23. The power supply as recited in claim 17 wherein said signal generator comprises a clock.