Method and apparatus for using pulse current to extend the functionality of a battery

• US 6,469,473 B1
• Filed: 03/16/2001
• Issued: 10/22/2002
• Est. Priority Date: 03/16/2001
• Status: Expired due to Fees

• Current Assignee: Battery Performance Technologies Incorporated
• Original Assignee: Battery Performance Technologies Incorporated
• Inventors: Schlicht, Michael
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/811,109
• Time in Patent Office: 585 Days
• Field of Search: 320/127, 320/129, 320/131, 320/135, 320/139, 320/141
• US Class Current: 320/131
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method to extend the functionality of a battery, the method comprising drawing power from the battery, and repetitively drawing a current pulse greater than the minimum conditioning current from the battery, thereby conditioning the battery.

Claims

1. A method of conditioning a battery while discharging the battery, the method comprising:

drawing power from the battery;

repetitively drawing a current pulse greater than the minimum conditioning current from the battery, thereby conditioning the battery.

2. The method of claim 1, wherein the minimum conditioning current is a function of the battery power remaining in the battery, and decreases as a function of a decrease of the battery voltage.

3. The method of claim 2, further comprising calculating the minimum conditioning current, comprising:

drawing a first current level from the battery at a first battery power;

determining whether a conditioning effect has been observed; and

if the conditioning effect has been observed, determining that the first current level is at least at the minimum conditioning current.

4. The method of claim 1, wherein a pulse width is between 5 μ

s and 500 μ

s.

5. The method of claim 1, wherein a pulse frequency is between 100 pulses per second and 1 pulse per minute.

6. The method of claim 1, wherein the pulse occurs at irregular intervals.

7. The method of claim 1, wherein the battery is used to drive a device, while the current pulses are being drawn.

8. The method of claim 1, further comprising:

isolating a device coupled to the battery from a voltage dip in response to the current pulse.

9. The method of claim 8, wherein the device is powered from an alternative power source while the current pulse is being drawn from the battery.

10. The method of claim 9, wherein the alternative power source is a capacitor, and wherein the capacitor is charged by the battery.

11. A method of conditioning a battery to eliminate voltage depression, the method comprising:

coupling a pulser between the battery and a device during use of the battery, the pulser repetitively drawing a current pulse greater than the minimum conditioning current from the battery, thereby conditioning the battery; and

removing the pulser from between the battery and the device after a period of time, the battery having been conditioned during this process such that the in-use time of the battery corresponds to the in-use time of the new battery.

12. The method of claim 11, wherein the period of time depends on an initial condition of the battery, such that less time is needed to condition a fairly new battery compared to an old battery.

13. The method of claim 12, wherein the period of time ranges from a few minutes to multiple discharge cycles.

14. The method of claim 11, wherein the battery is a rechargeable nickel cadmium (NiCad) battery.

15. An apparatus to improve functionality of a battery comprising:

a pulser to repetitively draw a current pulse greater than a minimum conditioning current from the battery, thereby conditioning the battery.

16. The apparatus of claim 15, wherein the minimum conditioning current is function of the battery power, and decreases as a function of a decrease of the battery voltage.

17. The apparatus of claim 16, wherein the pulser comprises:

a pulse generator to generate current pulses; and

such that a battery voltage is reduced to half its normal value.

18. The apparatus of claim 17, further comprising:

a switch to disconnect the pulser from a device coupled to the battery while the voltage is reduced; and

a secondary power source to power the device during the pulse.

19. The apparatus of claim 18, wherein the secondary power source comprises a capacitor.

20. The apparatus of claim 15, further comprising:

a delay logic to disconnect the pulser from the device prior to the pulse, and to recouple the battery to the device after a voltage spike.

21. An apparatus to condition a rechargeable battery during use comprising:

a pulse generator powered by the battery;

a control circuit for switching the pulse generator into the circuit periodically, to permit the pulse generator to repetitively draw a current pulse greater than the minimum conditioning current from the battery, thereby conditioning the battery.

22. The apparatus of claim 21, wherein the battery is a rechargeable nickel cadmium (NiCad) battery.

23. The apparatus of claim 21, further comprising:

a second switch to decouple the pulse generator an output of the apparatus, such that a device coupled to the output of the apparatus is not affected by a voltage dip as a result of the current pulse.

24. The apparatus of claim 23, further comprising:

a delay logic to decouple the pulse generator prior to the current pulse, and to recouple the pulse generator after a delay, such that a voltage spike resulting from a decrease in the current after the current pulse does not affect the device.

25. The apparatus of claim 21, wherein the control circuit comprises:

a first driver controlling the first switch, the first driver controlled by the pulse generator, the first driver disconnecting the pulse generator from an output of the apparatus during the pulse; and

a second driver controlling a second switch to couple a capacitor to the output of the apparatus during the pulse, such that the capacitor provides power to a device coupled to the output of the apparatus.

26. A method of conditioning a battery while discharging the battery, the method comprising:

drawing a first current level and a first voltage level from the battery;

drawing a current pulse at least ten times the first current level from the battery;

such that the voltage provided by the battery during the current pulse is one half the first voltage level.