Battery charger with enhanced charging and charge measurement processes

• US 6,232,750 B1
• Filed: 01/19/2000
• Issued: 05/15/2001
• Est. Priority Date: 06/08/1999
• Status: Expired due to Fees

• Current Assignee: Energy Micro AS
• Original Assignee: Energy Micro AS
• Inventors: Podrazhansky, Yury, Podrazhansky, Mikhail Y., Cope, Richard C.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TIBBITS, PIA FLORENCE
• Application Number:
  US09/487,693
• Time in Patent Office: 482 Days
• Field of Search: 320/139, 320/141, 320/145
• US Class Current: 320/139
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process

Abstract

A battery is rapidly charged utilizing a bipolar waveform (21, 22). The voltage, current, duration and frequency parameters of the bipolar waveform are selected to perform a number of actions: enhancing the mixing action at the battery electrodes; measuring the battery'"'"'s capacitance, condition, and level of impedance; modifying the mass transport process inside the battery; and reducing the concentration of the diffusion layer, the polarization concentration, and the overpotential. This reduces internal heat generation by providing for more efficient ion transport, reduced concentration gradients, and increased diffusion rates and intercalation speeds. A bipolar waveform can be in the form of sine waves, or other wave shapes. A charge pulse (11) is preferably followed by a small technical rest period (12), after which a discharge pulse (13) is applied followed, in turn, by a rest period (14). The bipolar waveform (21) is superimposed on one or more of the above. A second discharge pulse (15) is then applied followed by another rest period (16). A second bipolar waveform (22) is superimposed on either the second discharge pulse (15) or the second rest period (16). The second bipolar waveform (22) allows a measurement of the battery capacitance to be obtained and an evaluation of the charge of the battery to be derived. The charge cycle is repeated until a measured battery parameter attains a desired value indicative of a charged battery.

Claims

1. A method for charging a battery, comprising:

applying a charge pulse to said battery;

applying a discharge pulse to said battery;

waiting for a rest period after said discharge pulse;

applying an enhancement bipolar waveform to said battery during said rest period, said enhancement bipolar waveform having characteristics of a duration, a voltage level, a current level, a frequency, and a waveshape, wherein at least one of said characteristics is selected to enhance an ability of said battery to receive a next charge pulse;

applying a testing bipolar waveform having a testing frequency to said battery during either (i) said rest period and subsequent to said enhancement bipolar waveform, or (ii) a subsequent rest period, said testing frequency being different from said frequency of said enhancement bipolar waveform;

measuring predetermined characteristics of said battery during said testing bipolar waveform;

determining the state of charge of the battery based upon said predetermined characteristics which were measured during said testing bipolar waveform; and

adjusting at least one of said charge pulse, said discharge pulse, and said rest period, in response to said step of determining the state of charge of the battery.

2. The method of claim 1 wherein said enhancement bipolar waveform is applied at a predetermined point during said rest period.

3. The method of claim 1 and, between said charge pulse and said discharge pulse, further comprising the step of applying a short technical rest period.

4. The method of claim 1 and further comprising:

measuring a voltage level of said testing bipolar waveform applied to said battery;

measuring a current level of said testing bipolar waveform passed through said battery; and

determining an impedance of said battery by dividing said voltage level of said testing bipolar waveform by said current level of said testing bipolar waveform.

5. The method of claim 1 and further comprising:

measuring a voltage level of said battery during said charge pulse;

measuring a current level passed through said battery during said charge pulse;

determining an internal resistance of said battery based on said voltage level of said battery during said charge pulse and said current level passed through said battery during said charge pulse.

6. A method for charging a battery, comprising:

applying a charge pulse to said battery;

waiting for a rest period; and

applying an enhancement bipolar waveform to said battery during said rest period, said enhancement bipolar waveform having characteristics of a duration, a voltage level, a current level, a frequency, and a waveshape, wherein at least one of said characteristics is selected to enhance an ability of said battery to receive a next charge pulse;

applying a testing bipolar waveform having a testing frequency to said battery during either (i) said rest period and subsequent to said enhancement bipolar waveform, or (ii) a subsequent rest period, said testing frequency being different from said frequency of said enhancement bipolar waveform;

measuring predetermined characteristics of said battery during said testing bipolar waveform;

determining the state of charge of the battery based upon said predetermined characteristics which were measured during said testing bipolar waveform; and

adjusting at least one of said charge pulse and said rest period in response to said step of determining the state of charge of the battery.

7. The method of claim 6 and further comprising applying a discharge pulse to said battery after said step of applying said enhancement bipolar waveform.

8. The method of claim 6 wherein said enhancement bipolar waveform is applied at a predetermined point during said rest period.

9. The method of claim 6 wherein said rest period is a technical rest period.

10. The method of claim 6 and further comprising:

measuring a voltage level of said testing bipolar waveform applied to said battery;

measuring a current level of said testing bipolar waveform passed through said battery; and

determining an impedance of said battery by dividing said voltage level of said testing bipolar waveform by said current level of said testing bipolar waveform.

11. The method of claim 6 and further comprising:

measuring a voltage level of said battery during said charge pulse;

measuring a current level passed through said battery during said charge pulse;

determining an internal resistance of said battery based on said voltage level of said battery during said charge pulse and said current level passed through said battery during said charge pulse.

12. A method for charging a battery, comprising:

applying a charge pulse to said battery;

applying an enhancement bipolar waveform to said battery during said charge pulse, said enhancement bipolar waveform having characteristics of a duration, a voltage level, a current level, a frequency, and a waveshape,

wherein at least one of said characteristics is selected to enhance an ability of said battery to receive said charge pulse.

13. The method of claim 12 and further comprising the step of waiting for a rest period after said steps of applying said charge pulse and said enhancement bipolar waveform.

14. The method of claim 13 and further comprising the step of applying a discharge pulse to said battery after said steps of applying said charge pulse and said enhancement bipolar waveform and waiting for said rest period.

15. The method of claim 12 and further comprising the step of waiting for a technical rest period after said steps of applying said charge pulse and said enhancement bipolar waveform.

16. The method of claim 15 and further comprising the step of applying a discharge pulse to said battery after said steps of applying said charge pulse and said enhancement bipolar waveform and waiting for said technical rest period.

17. The method of claim 12 and further comprising the step of applying a discharge pulse to said battery after said steps of applying said charge pulse and said enhancement bipolar waveform.

18. The method of claim 12 wherein said enhancement bipolar waveform is applied at a predetermined point during said charge pulse.

19. A method for charging a battery, comprising:

applying a charge pulse to said battery;

applying an enhancement bipolar waveform to said battery during said charge pulse, said enhancement bipolar waveform having characteristics of a duration, a voltage level, a current level, a frequency, and a waveshape, wherein at least one of said characteristics is selected to enhance an ability of said battery to receive said charge pulse;

waiting for a rest period;

applying a testing bipolar waveform having a testing frequency to said battery during said rest period, said testing frequency being different from said frequency of said enhancement bipolar waveform;

measuring predetermined characteristics of said battery during said testing bipolar waveform; and

determining the state of charge of the battery based upon said predetermined characteristics which were measured during said testing bipolar waveform.

20. The method of claim 19 and further comprising:

adjusting said charge pulse in response to said step of determining the state of charge of the battery.

21. The method of claim 19 and further comprising:

measuring a voltage level of said testing bipolar waveform applied to said battery;

measuring a current level of said testing bipolar waveform passed through said battery; and

determining an impedance of said battery by dividing said voltage level of said testing bipolar waveform by said current level of said testing bipolar waveform.

22. The method of claim 19 and further comprising:

measuring a voltage level of said battery during said charge pulse;

measuring a current level passed through said battery during said charge pulse;

determining an internal resistance of said battery based on said voltage level of said battery during said charge pulse and said current level passed through said battery during said charge pulse.

23. A method for charging a battery, comprising:

applying a charge pulse to said battery;

applying an enhancement bipolar waveform to said battery during said charge pulse, said enhancement bipolar waveform having characteristics of a duration, a voltage level, a current level, a frequency, and a waveshape,

wherein at least one of said characteristics is selected to enhance an ability of said battery to receive a subsequent charge pulse.

24. The method of claim 23 and further comprising the step of waiting for a rest period after said steps of applying said charge pulse and said enhancement bipolar waveform.

25. The method of claim 24 and further comprising the step of applying a discharge pulse to said battery after said steps of applying said charge pulse and said enhancement bipolar waveform and waiting for said rest period.

26. The method of claim 23 and further comprising the step of waiting for a technical rest period after said steps of applying said charge pulse and said enhancement bipolar waveform.

27. The method of claim 26 and further comprising the step of applying a discharge pulse to said battery after said steps of applying said charge pulse and said enhancement bipolar waveform and waiting for said technical rest period.

28. The method of claim 23 and further comprising the step of applying a discharge pulse to said battery after said steps of applying said charge pulse and said enhancement bipolar waveform.

29. The method of claim 23 wherein said enhancement bipolar waveform is applied at a predetermined point during said charge pulse.

30. A method for charging a battery, comprising:

applying a charge pulse to said battery;

applying an enhancement bipolar waveform to said battery during said charge pulse, said enhancement bipolar waveform having characteristics of a duration, a voltage level, a current level, a frequency, and a waveshape, wherein at least one of said characteristics is selected to enhance an ability of said battery to receive a subsequent charge pulse;

applying a rest period;

applying a testing bipolar waveform having a testing frequency to said battery during said rest period, said testing frequency being different from said frequency of said enhancement bipolar waveform;

measuring predetermined characteristics of said battery during said testing bipolar waveform; and

determining the state of charge of the battery based upon said predetermined characteristics which were measured during said testing bipolar waveform.

31. The method of claim 30 and further comprising:

adjusting said subsequent charge pulse in response to said step of determining the state of charge of the battery.

32. The method of claim 30 and further comprising:

measuring a voltage level of said testing bipolar waveform applied to said battery;

measuring a current level of said testing bipolar waveform passed through said battery; and

determining an impedance of said battery by dividing said voltage level of said testing bipolar waveform by said current level of said testing bipolar waveform.

33. The method of claim 30 and further comprising:

measuring a voltage level of said battery during said charge pulse;

measuring a current level passed through said battery during said charge pulse;

determining an internal resistance of said battery based on said voltage level of said battery during said charge pulse and said current level passed through said battery during said charge pulse.

34. A method for charging a battery, comprising:

applying a charge pulse to said battery;

applying a discharge pulse to said battery; and

applying an enhancement bipolar waveform to said battery during said discharge pulse, said enhancement bipolar waveform having characteristics of a duration, a voltage level, a current level, a frequency, and a waveshape,

wherein at least one of said characteristics is selected to enhance an ability of said battery to receive a subsequent charge pulse.

35. The method of claim 34 and further comprising the step of waiting for a rest period between said charge pulse and said discharge pulse.

36. The method of claim 34 and further comprising the step of waiting for a technical rest period between said charge pulse and said discharge pulse.

37. The method of claim 34 and further comprising the steps of:

waiting for a subsequent rest period after said discharge pulse;

applying a subsequent discharge pulse to said battery after said subsequent rest period;

applying a subsequent bipolar waveform to said battery during said subsequent discharge pulse.

38. The method of claim 37 wherein said enhancement bipolar waveform is applied at a predetermined point during said subsequent discharge pulse.

39. The method of claim 37 wherein said enhancement bipolar waveform is applied at a predetermined point during said discharge pulse.

40. The method of claim 34 wherein said enhancement bipolar waveform is applied at a predetermined point during said discharge pulse.

41. A method for charging a battery, comprising:

applying a charge pulse to said battery;

applying a discharge pulse to said battery; and

applying an enhancement bipolar waveform to said battery during said discharge pulse, said enhancement bipolar waveform having characteristics of a duration, a voltage level, a current level, a frequency, and a waveshape, wherein at least one of said characteristics is selected to enhance an ability of said battery to receive a subsequent charge pulse;

applying a rest period;

applying a testing bipolar waveform having a testing frequency to said battery during said rest period, said testing frequency being different from said frequency of said enhancement bipolar waveform;

measuring predetermined characteristics of said battery during said testing bipolar waveform; and

determining the state of charge of the battery based upon said predetermined characteristics which were measured during said testing bipolar waveform.

42. The method of claim 41 and further comprising:

adjusting at least one of said charge pulse, said discharge pulse, and said rest period, in response to said step of determining the state of charge of the battery.

43. The method of claim 41 and further comprising:

measuring a voltage level of said testing bipolar waveform applied to said battery;

measuring a current level of said testing bipolar waveform passed through said battery; and

determining an impedance of said battery by dividing said voltage level of said testing bipolar waveform by said current level of said testing bipolar waveform.

44. The method of claim 41 and further comprising:

measuring a voltage level of said battery during said charge pulse;

measuring a current level passed through said battery during said charge pulse;

determining an internal resistance of said battery based on said voltage level of said battery during said charge pulse and said current level passed through said battery during said charge pulse.

45. An apparatus for charging a battery comprising:

a charging circuit for applying charge pulses to said battery;

a discharging circuit for applying discharge pulses to said battery;

a bipolar waveform circuit for applying bipolar waveforms to said battery, said bipolar waveforms having characteristics of a duration, a voltage level, a current level, a frequency, and a waveshape, and wherein at least one of said characteristics is selected to enhance an ability of said battery to receive said charge pulses; and

a controller, connected to said charging circuit, said discharging circuit, and said bipolar waveform circuit, said controller causing said charging circuit to apply said charge pulses, said controller causing said discharging circuit to apply said discharge pulses, said controller causing said bipolar waveform circuit to apply said bipolar waveforms during said charge pulses.

46. An apparatus for charging a battery comprising:

a charging circuit for applying charge pulses to said battery;

a discharging circuit for applying discharge pulses to said battery;

a bipolar waveform circuit for applying an enhancement bipolar waveform and a testing bipolar waveform to said battery, said enhancement bipolar waveform having characteristics of a duration, a voltage level, a current level, a frequency, and a waveshape, and wherein at least one of said characteristics is selected to enhance an ability of said battery to receive said charge pulses, said testing bipolar waveform having a testing frequency, said testing frequency being different from said frequency of said enhanced bipolar waveform; and

a controller, connected to said charging circuit, said discharging circuit, and said bipolar waveform circuit, said controller causing said charging circuit to apply said charge pulses, said controller causing said discharging circuit to apply said discharge pulses, said controller causing said charge pulses and said discharge pulses to be separated by wait periods, said controller causing said bipolar waveform circuit to apply said enhancement bipolar waveform during predetermined wait periods and to apply said testing bipolar waveform during said rest period and subsequent to said enhancement bipolar waveform, said testing frequency being different from said frequency of said enhanced bipolar waveform, said controller measuring predetermined characteristics of said battery during said testing bipolar waveform, determining the state of charge of the battery based upon said predetermined characteristics which were measured during said testing bipolar waveform, and adjusting at least one of said charge pulse, said discharge pulse, and said rest period, in response to said state of charge of the battery.

47. An apparatus for charging a battery comprising:

a charging circuit for applying charge pulses to said battery;

a discharging circuit for applying discharge pulses to said battery;

a bipolar waveform circuit for applying bipolar waveforms to said battery, said bipolar waveforms having characteristics of a duration, a voltage level, a current level, a frequency, and a waveshape, and wherein at least one of said characteristics is selected to enhance an ability of said battery to receive said charge pulses; and

a controller, connected to said charging circuit, said discharging circuit, and said bipolar waveform circuit, said controller causing said charging circuit to apply said charge pulses, said controller causing said discharging circuit to apply said discharge pulses, said controller causing said bipolar waveform circuit to apply said bipolar waveforms during said discharge pulses.

48. An apparatus for charging a battery comprising:

a charging circuit for applying charge pulses to said battery;

a discharging circuit for applying discharge pulses to said battery;

a bipolar waveform circuit for applying an enhancement bipolar waveform and a testing bipolar waveform to said battery, said enhancement bipolar waveform having characteristics of a duration, a voltage level, a current level, a frequency, and a waveshape, and wherein at least one of said characteristics is selected to enhance an ability of said battery to receive said charge pulses, said testing bipolar waveform having a testing frequency, said testing frequency being different from said frequency of said enhanced bipolar waveform; and

a controller, connected to said charging circuit, said discharging circuit, and said bipolar waveform circuit, said controller causing said charging circuit to apply said charge pulses, said controller causing said discharging circuit to apply said discharge pulses, said controller causing said charge pulses and said discharge pulses to be separated by wait periods, said controller causing said bipolar waveform circuit to apply said enhancement bipolar waveform during predetermined wait periods and to apply said testing bipolar waveform during a subsequent rest period, said testing frequency being different from said frequency of said enhanced bipolar waveform, said controller measuring predetermined characteristics of said battery during said testing bipolar waveform, determining the state of charge of the battery based upon said predetermined characteristics which were measured during said testing bipolar waveform, and adjusting at least one of said charge pulse, said discharge pulse, and said rest period, in response to said state of charge of the battery.