Method and apparatus for rapidly charging and reconditioning a battery

• US 5,998,968 A
• Filed: 07/25/1997
• Issued: 12/07/1999
• Est. Priority Date: 01/07/1997
• Status: Expired due to Fees

• Current Assignee: ION Control Solutions
• Original Assignee: ION Control Solutions
• Inventors: Stefansson, Hafthor, Pittman, Ronald W.
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US08/900,821
• Time in Patent Office: 865 Days
• Field of Search: 320/124, 320/125, 320/128, 320/130, 320/133, 320/139, 320/141, 320/145, 320/157, 320/159, 320/160, 320/162, 320/164, 320/DIG. 16, 320/FOR 118, 320/FOR 120 , 320/FOR 121, 320/FOR 123, 320/FOR 129, 320/FOR 130, 320/FOR 138
• US Class Current: 320/130
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process

Abstract

An improved battery charger and reconditioner employs a charging sequence calling for a discharge pulse to be applied substantially immediately before a charging pulse to effectively lower the impedance of the subject battery and to thereby more effectively charge the battery at a lower voltage level. The apparatus and method of the invention enhances the current receiving properties of the battery to lower thermal properties associated with charging and to more efficiently and more rapidly charge a subject battery. The charging sequence reconditions a battery by applying the improved sequence so as to rejuvenate an otherwise damaged battery. The invention also provides a method and means for formatting a battery and for removing dendritic formations which occur in a battery. Further, methods for aborting battery charging and for detecting abnormal conditions are also provided by the present invention.

Claims

1. A process for rapidly charging a battery by a battery charger having an input connected to a source of power, the battery charger providing alternating charge and discharge pulses to the battery, the charging process comprising the steps of:

a) partially discharging the battery by means of a discharge pulse substantially immediately prior to a charge pulse to lower the impedance and the voltage of the battery prior to the charge pulse being delivered to the battery;

b) substantially immediately after partially discharging the battery, supplying the charge pulse to the battery, the charge delivered to the battery during the charge pulse being greater than the charge drained from the battery during the discharge pulse, the ratio of the duration of the charge pulse to the discharge pulse being greater than 10 to 1.

c) waiting a rest period after the charge pulse of step b) and prior to applying a subsequent discharge pulse to the battery to allow the battery to at least partially stabilize; and

d) repeating the above steps.

2. The process of claim 1, wherein the rest period is shorter in duration than the charge pulse of step b) over the majority of the charging process.

3. The process of claim 1, wherein the battery charger provides a constant current supply.

4. The process of claim 3, wherein the battery charger is one of a linear or a switching constant current supply.

5. The process of claim 1 further comprising the step of detecting the charge of the battery, initiating the charging process upon detecting a first predetermined threshold value, and terminating the charging process upon detecting a second predetermined threshold value.

6. The process of claim 1 further comprising the step of measuring the voltage of the battery, initiating the charging process upon detecting a first predetermined minimum voltage value, and terminating the charging process upon detecting a second predetermined maximum voltage value.

7. The process of claim 6, wherein the step of measuring the voltage of the battery occurs during the discharge pulse.

8. The process of claim 7, wherein the step of measuring the voltage of the battery occurs substantially at the end of the discharge pulse and before the charge pulse begins.

9. The process of claim 6 further comprising the step of trickle charging the battery near the end of the charging process upon measuring a predetermined trickle threshold voltage value intermediate the first and second voltage values, the trickle charge comprising steps a) through d) with the duration of the rest period of step c) extended to be about equal to or greater than the duration of the charge pulse of step b).

10. The process of charging a battery of claim 9, wherein the step of trickle charging is conducted over a predetermined fixed period of time.

11. The process of claim 1 further comprising the step of monitoring the voltage of the battery and preventing the voltage of the battery from exceeding the battery'"'"'s barrier potential, thereby preventing heat generation and damage to the battery during the charging process.

12. The process of claim 1, wherein the ratio of charge delivered to the battery during the charge pulse to the charge drained from the battery during the discharge pulse is about between 10 to 1 and 200 to 1.

13. The process of claim 1, wherein the battery is a lead-based secondary cell type rechargeable battery.

14. The process of claim 13, wherein the discharge pulse has a duration of about no more than 10 milliseconds.

15. The process of claim 13, wherein the charge pulse has a duration of about 100 milliseconds.

16. The process of claim 13, wherein the rest period has a duration of about 1 millisecond over a significant portion of the charging process.

17. The process of claim 13, wherein the ratio of the duration of said charge pulse to the duration of said discharge pulse is within a range of about between 10 to 1 and 100 to 1.

18. The process of charging a battery of claim 13, wherein the ratio of the duration of said charge pulse to said rest period is within a range of about 10 to 1 and 200 to 1.

19. The process of claim 13, wherein the battery has a defined charge storage capacity and the charging rate of the battery charger is approximately equal to the charge storage capacity of the battery being charged.

20. The process of claim 1, wherein the battery is a nickel-based secondary cell.

21. The process of claim 20, wherein the battery is one of a group consisting of Nickel--Cadmium and Nickel Metal Hydride.

22. The process of claim 20, wherein the discharge pulse has a duration of about no more than 10 milliseconds.

23. The process of claim 20, wherein the charge pulse has a duration of about 200 milliseconds.

24. The process of claim 20, wherein the rest period has a duration of about 50 milliseconds over a significant portion of the charging process.

25. The process of claim 20, wherein the ratio of the duration of said charge pulse to the duration of said discharge pulse is within a range of about between 10 to 1 and 100 to 1.

26. The process of claim 20, wherein the ratio of the duration of said charge pulse to said rest period is within a range of about between 3 to 1 and 45 to 1 over a majority of the charging process.

27. The process of claim 20 further comprising the step of taking periodic measurements of the battery voltage throughout the charging process, temporarily suspending the charge pulse and lengthening the rest period based upon taking a voltage measurement that exceeds a predetermined voltage threshold, applying a discharge pulse at the end of the rest period and taking a subsequent voltage measurement during the discharge period, and terminating charging operation should the subsequent voltage measurement exceed the predetermined voltage threshold or continuing the charging process should the subsequent voltage measurement be less than the predetermined voltage threshold.

28. The process of claim 20, wherein the battery has a defined charge storage capacity and the charging rate of the battery charger is up to five times the charge storage capacity of the battery being charged.

29. The process of claim 1, wherein the charge pulse, discharge pulse, and rest period are collectively less than one second in duration.

30. The process of claim 1, wherein the battery charger provides a constant current supply comprising a plurality of selectable constant current charge levels.

31. The process of claim 30 further comprising the step of selecting a desired constant current charge level from the plurality of constant current charge levels.

32. The process of claim 31, wherein the step of selecting the desired constant current charge level is accomplished by a microprocessor.

33. The process of claim 31, wherein the step of selecting the desired constant current charge level is accomplished by selecting from a plurality of resistors.

34. The process of claim 31, wherein the step of selecting the desired constant current charge level is accomplished by manipulating a switch having a plurality of settings.

35. The process of claim 1 further comprising the step of measuring the voltage of the battery and comparing a first measured battery voltage level with a subsequent second measured battery voltage level, and, upon detecting that the first measured voltage level is greater than the second measured voltage level, terminating the charging process.

36. The process of claim 35 further comprising the step of providing indication of a battery fault condition upon detecting that the first measured voltage level is greater than the second measured voltage level.

37. The process of claim 1 further comprising the step of measuring the voltage of the battery and comparing a first measured battery voltage level with a subsequent second measured battery voltage level, and upon detecting that the difference between the first and second measured values exceeds a predetermined maximum value, terminating the charging process.

38. The process of claim 37 further comprising the step of providing indication of a battery fault condition upon detecting that the difference between the first and second measured voltage levels exceeds the predetermined maximum value.

39. The process of claim 1 further comprising the step of measuring the voltage of the battery before initiating steps a) through d) and providing a predetermined time limit for the duration of the charging process based upon the measured voltage and terminating the charging process upon reaching the time limit.

40. The process of claim 39 further comprising the step of providing indication of a battery fault condition upon reaching the time limit.

41. The process of claim 1 further comprising the step of applying a pre-charge discharge pulse prior to initiating steps a) through d), measuring the battery'"'"'s pre-charge voltage during the pre-charge discharge pulse, and determining a charge process time limit based upon the battery'"'"'s measured pre-charge voltage.

42. The process of claim 1 further comprising the step of measuring the voltage of the battery and varying one or more of the discharge pulse, charge pulse, and rest period in accordance with one or more predetermined threshold voltage values.

43. The process of claim 42, wherein the duration of the rest period is increased as the measured voltage increases during the charging process.

44. The process of claim 1, wherein the battery charger is microprocessor-based and includes memory adapted to store the predetermined sequencing of the alternating charge pulse, discharge pulse, and rest period.

45. The process of claim 1, wherein the battery charger is driven by an application specific integrated circuit adapted to provide the predetermined sequencing of alternating constant charge pulse, discharge pulse, and rest period.

46. The process of claim 1 comprising the further step of providing a charge initialization stage prior to steps a) through d) that is essentially identical to steps a) through d), except with the rest period of the charge initialization stage being substantially longer than the rest period of step d).

47. The process of claim 46, wherein the charge initialization stage continues for a fixed predetermined period of time.

48. An apparatus for rapidly charging a battery comprising:

an output adapted to be electrically connected to a battery;

a charge pulse generator adapted to provide a charge pulse at said output to charge the battery;

a discharge device adapted to provide a discharge pulse at said output to drain current from the battery to lower the impedance of the battery, the ratio of the duration of the charge pulse to the discharge pulse being greater than 10 to 1; and

a control device alternatingly connecting said discharge device, and said charge pulse generator to said output so as to alternatingly provide said discharge pulse, and charge pulse, and an electrically neutral rest period, respectively, to the battery, said discharge pulse, charge pulse, and rest period being applied to the battery in a predetermined standard charging sequence in which said discharge pulse is applied substantially immediately prior to said charge pulse.

49. The battery charging apparatus of claim 48, wherein said charge pulse generator comprises a constant current supply.

50. The battery charging apparatus of claim 49, wherein said constant current supply is one of a linear and a switching constant current supply.

51. The battery charging apparatus of claim 48, wherein the battery is a lead-based secondary cell rechargeable battery.

52. The battery charging apparatus of claim 51, wherein said discharge pulse has a duration of about no more than 10 milliseconds.

53. The battery charging apparatus of claim 51, wherein the charging pulse has a duration of about 100 milliseconds.

54. The battery charging apparatus of claim 51, wherein the rest period has a duration of about 1 millisecond over a significant portion of the charging process.

55. The battery charging apparatus of claim 51, wherein the ratio of the duration of said charging pulse to the duration of said discharge pulse is within a range of about between 10 to 1 and 100 to 1.

56. The battery charging apparatus of claim 51, wherein the ratio of the duration of said charging period to said rest period is within a range of about between 10 to 1 and 200 to 1.

57. The battery charging apparatus of claim 51, wherein the battery has a defined charge storage capacity and the charging rate of said battery charging apparatus is up to one and one-half times said battery charge storage capacity.

58. The battery charging apparatus of claim 48, wherein the battery is one of a group consisting of Nickel Cadmium and Nickel Metal Hydride types of batteries.

59. The battery charging apparatus of claim 58, wherein said discharge pulse has a duration of about no more than 10 milliseconds.

60. The battery charging apparatus of claim 58, wherein the charging pulse has a duration of about 200 milliseconds.

61. The battery charging apparatus of claim 58, wherein the rest period has a duration of about 50 milliseconds over a significant portion of the charging sequence.

62. The battery charging apparatus of claim 58, wherein the ratio of the duration of said charging pulse to the duration of said discharge pulse is within a range of about between 10 to 1 and 100 to 1.

63. The battery charging apparatus of claim 58, wherein the ratio of the duration of said charge pulse to said rest period is within a range of about between 10 to 1 and 200 to 1.

64. The battery charging apparatus of claim 58, wherein the battery has a defined charge storage capacity and the charging rate of said battery charging apparatus is up to five times said charge storage capacity.

65. The battery charging apparatus of claim 58, wherein said control device is adapted to provide a charge initialization sequence prior to said standard charging sequence in which said discharge pulse is greater in duration than during said standard charging sequence.

66. The battery charging apparatus of claim 48, wherein said discharge device comprises a load electrically connected to the battery, whereby during the discharge pulse current is drained from the battery through the load.

67. The battery charging apparatus of claim 48, wherein said discharge device comprises a switching element and a resistor, said switching element is disposed in series with the battery and said resistor, whereby during the discharge pulse current is drained from the battery through said switching element and said resistor to ground and said resistor dissipates power stored in the battery.

68. The battery charging apparatus of claim 67 wherein the ohmic value and power rating of said resistor determines the rate at which power is dissipated from the battery and determines the ratio of the durations of the charge and discharge pulses.

69. The battery charging apparatus of claim 67, wherein said switching element is a semiconductor-based element.

70. The battery charging apparatus of claim 69, wherein said switching element comprises at least one transistor in which the current flowing from the battery through said resistor flows through a collector and emitter of said transistor.

71. The battery charging apparatus of claim 70, wherein said at least one transistor is a MOSFET-type transistor.

72. The battery charging apparatus of claim 67, wherein current is drawn through said resistor at about five to six times the charge capacity rating of the battery during said discharge pulse.

73. The battery charging apparatus of claim 49 further comprising a battery charge detector adapted to be connected to the battery, said standard charging sequence being initiated upon said detector detecting a first threshold value and terminated upon said detector detecting a second threshold value.

74. The battery charging apparatus of claim 73, wherein said battery charge detector measures the voltage level of the battery, and said first and second threshold values are minimum and maximum voltage measurements, respectively.

75. The battery charging apparatus of claim 74, wherein said battery charge detector measures the voltage level of the battery during the discharge pulse.

76. The battery charging apparatus of claim 75, wherein said battery charge detector measures the voltage level of the battery substantially at the end of said discharge pulse and before said charge pulse.

77. The battery charging apparatus of claim 74, wherein said control device is adapted to effect a trickle charge sequence near the end of said standard charging sequence upon said battery charge detector detecting a third predetermined voltage value intermediate said first and second voltage values, and said trickle charge sequence is essentially the same as said standard charging sequence except that the duration of said rest period is about equal to or greater than the duration of said charge pulse.

78. The battery charging apparatus of claim 77, wherein said trickle charge is conducted over a predetermined fixed period of time.

79. The battery charging apparatus of claim 73, wherein said battery charge detector monitors the voltage of the battery and terminates the charging process to prevent the voltage of the battery from exceeding the battery'"'"'s barrier potential, thereby preventing heat generation and potential injury to the battery during the charging process.

80. The battery charging apparatus of claim 48 further comprising an opto-isolator device, said charge pulse generator comprising a power supply having a ground plane, said opto-isolator being electrically disposed intermediate said power supply ground plane and the ground plane of said control device.

81. The battery charging apparatus of claim 80, wherein said opto-isolator device comprises a light emitting diode operating on said control device ground plane and operatively coupled with a transistor photosensitive device operating on said power supply ground plane, and said transistor photosensitive device senses the state of said light emitting diode.

82. The battery charging apparatus of claim 48, wherein said discharge device lowers the impedance of the battery substantially immediately prior to said charge pulse, thereby enhancing the current receiving properties of the battery.

83. The battery charging apparatus of claim 48, wherein said discharge device reduces the natural capacitance of the battery.

84. The battery charging apparatus of claim 48, further comprising a voltage selector connected to said charge pulse generator and having a plurality of voltage level settings corresponding to acceptable rated voltage levels of batteries to be connected to said battery charging apparatus for charging.

85. The battery charging apparatus of claim 84, wherein said voltage selector is set to a selected one of said plurality of voltage settings corresponding to the rated voltage of the battery being charged.

86. The battery charging apparatus of claim 85 further comprising a battery charge detector connected to the battery, the charging process being initiated upon said detector detecting a first threshold value and terminated upon said detector detecting a second threshold value, and wherein said battery charge detector measures the voltage level of the battery, said first and second threshold values are minimum and maximum voltage measurements, respectively, and the value of said first minimum threshold value is about two-thirds of the selected voltage.

87. The battery charging apparatus of claim 86, wherein said selected voltage setting is 12V and said first minimum threshold value is about 8V.

88. The battery charging apparatus of claim 48, wherein said control device further comprises a battery charge detector and a comparator, said detector is adapted to measure the voltage level of the battery, said comparator includes a first input receiving a first measured battery voltage value and a second input receiving a subsequent second measured battery voltage value, and, upon said comparator detecting that said first measured voltage value is greater than said second measured voltage value, said control device terminating the standard charging sequence.

89. The battery charging apparatus of claim 88 further comprising an indicator, said indicator providing indication that a battery fault condition exists upon said comparator detecting that said first measured value is greater than said second measured value.

90. The battery charging apparatus of claim 48, wherein said control device further comprises a battery charge detector and a comparator, said detector is adapted to measure battery voltage, said comparator includes a first input receiving a first measured battery voltage value and a second input receiving a subsequent second measured battery voltage value, and, upon said comparator detecting that the difference between said first and second measured values exceeds a predetermined maximum value, said control device terminating the charging operation.

91. The battery charging apparatus of claim 90 further comprising an indicator, said indicator providing indication that a battery fault condition exists upon said comparator detecting that the difference between the first and second measured values exceeds said predetermined maximum value.

92. The battery charging apparatus of claim 48 further comprising a clock, said control device terminating the charging process upon said clock reaching a predetermined time limit.

93. The battery charging apparatus of claim 92 further comprising an indicator, said indicator providing indication that a battery fault condition exists upon said control device reaching said time limit prior to terminating charging operation.

94. The battery charging apparatus of claim 92 further comprising a battery voltage detector adapted to measure battery voltage, said control device applying a discharge pulse prior to initiating said standard charging sequence and measuring the battery'"'"'s pre-charge voltage, said control device determining said time limit based upon said battery pre-charge voltage.

95. The battery charging apparatus of claim 48 further comprising a battery voltage detector adapted to measure the voltage of the battery, wherein said control device varies one or more of the discharge pulse, charge pulse, and rest period in accordance with one or more predetermined threshold voltage values.

96. The battery charging apparatus of claim 94, wherein said control device extends the duration of the rest period as the measured voltage increases during the charging process.

97. The battery charging apparatus of claim 48, wherein said control device is either microprocessor-based or is an application specific integrated circuit.

98. A method of formatting a battery by a battery charger adapted to provide alternating charge and discharge pulses to the battery, the formation method comprising the steps of:

providing a first formation sequence comprising the steps of;

a) applying a first charge pulse to the battery;

b) resting a first wait period to allow the battery to at least partially stabilize;

c) measuring the charge of the battery and repeating steps a) and b) until the battery reaches a first charge threshold, upon detecting the first charge threshold, transitioning the battery charger from the first formation sequence to a second formation sequence comprising the steps of;

d) partially discharging the battery substantially immediately prior to applying a charge pulse to reduce the impedance of the battery;

e) substantially immediately after discharging the battery, applying a charge pulse to the battery, the ratio of the duration of the charge pulse to the discharge pulse being greater than 10 to 1;

f) resting a second wait period prior to applying a subsequent discharge pulse; and

g) repeating steps d) through f) until the battery reaches a second charge threshold higher than said first charge threshold.

99. The battery formation method of claim 98, wherein the step of measuring the charge of the battery includes measuring the voltage level of the battery.

100. The battery formation method of claim 98, wherein the step of measuring the charge of the battery occurs during the discharge period.

101. The battery formation method of claim 98 further comprising the step of terminating the formation process upon detecting a bad battery condition based upon an excessive voltage level sensed at the beginning of the formation process.

102. The battery formation method of claim 98 further comprising the step of comparing a first measured battery voltage level with a subsequent second measured battery voltage level, and, upon detecting that the first measured value is greater than the second measured value, terminating the formation process.

103. The battery formation method of claim 98, wherein the charge pulse is a constant current charge.

104. The battery formation method of claim 98, wherein the battery charger is one of a microprocessor-based controller or an application specific integrated circuit.

105. A process for reconditioning a battery suffering from decreased charge capacity due to the effects of memory, the reconditioning process comprising the steps of:

a) charging the battery over a period of time by a battery charger adapted to implement a charging process comprising the steps of;

1) partially discharging the battery by means of a discharge pulse substantially Immediately prior to a charge pulse to reduce the impedance of the battery;

2) substantially immediately after discharging the battery, applying a charge pulse to the battery, the ratio of the duration of the charge pulse to the discharge pulse being greater than 10 to 1;

3) allowing the battery to at least partially stabilize by waiting a rest period prior to applying a subsequent discharge pulse; and

4) repeating the above steps until the charging process is terminated;

b) discharging a significant portion of the charge stored by the battery; and

c) repeatedly recharging the battery according to steps

     1) through

     4) after each discharge of step b) until the battery substantially regains its original charge capacity, thereby enhancing battery performance and life.

106. The process of claim 105, wherein the battery charger provides a constant current supply to the battery.

107. The process of claim 105, wherein the battery substantially regains its original charge in about four to six repetitions of steps a) and b).

108. The process of claim 105, wherein the battery regains about 95% of its original charge capacity.

109. An apparatus for rapidly charging a plurality of battery types having different rated voltages and different rated charge capacities, said charging apparatus comprising:

an output adapted to be electrically connected to a battery;

a charge pulse generator add to provide a charge pulse at said output to charge the battery;

a discharge device adapted to provide a discharge pulse at said outlet to drain current from the battery to lower the impedance of the battery;

a control device alternatingly connecting said discharge device and said charge pulse generator to said output so as to alternatingly provide said discharge pulse, said charge pulse, and an electrically neutral rest period, respectively, to the battery, said discharge pulse, charge pulse, and rest period being applied to the battery in a predetermined standard charging sequence in which said discharge pulse is applied substantially immediately prior 1;

0 said charge pulse, the ratio of the duration of the charge pulse to the discharge pulse being greater than 10 to 1, said control device adapted to deliver said charge pulse at a rate acceptable to any and all of the plurality of battery types according to the lowest current rating and the highest voltage rating of the plurality of battery types so as to provide an acceptable level of current drain from any one of the plurality of battery types being charged.

110. The battery charging apparatus of claim 109, wherein said charge current generator is a constant current supply.

111. The battery charging apparatus of claim 109, wherein said constant current supply is one of a linear or a switching constant current supply.

112. The battery charging apparatus of claim 109, wherein the battery is a lead-based type battery and the discharge device drains current from the battery at a rate of about five to six times the rated charge capacity of the battery.

113. The battery charging apparatus of claim 109, wherein the battery is a nickel-based secondary cell rechargeable battery.

114. The battery charging apparatus of claim 113, wherein the battery is one of a group consisting of Nickel Cadmium and Nickel Metal Hydride type batteries and the discharge device drains current from the battery at a rate of about two times the rated charge capacity of the battery.

115. The battery charging apparatus of claim 109, wherein said control device is one of a microprocessor-based controller and an application specific integrated circuit.

116. The battery charging apparatus of claim 109, wherein said discharge device is adapted to provide a selectable rate of current drain through the battery.

117. The battery charging apparatus of claim 116, wherein said control device is adapted to select the rate of current drain through the discharge device to match the particular type of battery being charged to optimize current drain through the battery.

118. The battery charging apparatus of claim 116, wherein said discharge device includes a plurality of resistors, each one of said resistors corresponding to one of a plurality of selectable rates of current drain through the battery.

119. The battery charging apparatus of claim 118, wherein the ohmic value of each of said plurality of resistors determines the rate at which power is dissipated from the battery and determines the ratio of the charge to discharge pulse durations.

120. The battery charging apparatus of claim 119, wherein said control device includes a microprocessor, and said microprocessor selects one of said resistors to effect a particular rate of current drain from the battery.

121. The battery charging apparatus of claim 119, wherein said control device includes a switch having a plurality of selectable positions corresponding and electrically connected to said plurality of resistors, and said switch is placed in a selected position corresponding to one of said resistors to effect a particular rate of current drain from the battery.

122. The battery charging apparatus of claim 116, wherein said control device is adapted to detect the type of battery connected to the battery charging apparatus.

123. A process for removing dendritic formations formed on a rechargeable battery to restore lost charging capacity to the battery, said dendritic removal process comprising the steps of:

charging the battery over a period of time by a battery charger adapted to implement a charging process comprising the steps of;

1) partially discharging the battery by means of a discharge pulse substantially immediately prior to a charge pulse to reduce the impedance of the battery;

2) substantially immediately after discharging the battery, applying a charge pulse to the battery, the ratio of the duration of the charge pulse to the discharge pulse being greater than 10 to 1;

3) allowing the battery to at least partially stabilize by waiting a rest period prior to applying a subsequent discharge pulse; and

4) repeating the above steps until the charging process is terminated;

b) discharging a significant portion of the charge stored by the battery; and

c) repeatedly recharging the battery according to steps

     1) through

     4) after each discharge of step b) until thc dendritic formations are significantly reduced, thereby enhancing battery performance and life.

124. The process of claim 123, wherein the battery charger includes a constant current supply.

125. The process of claim 123, wherein the constant current supply is one of a linear or a switching constant current supply.

126. The process of claim 123, wherein the battery is a lead-based type battery and the battery is discharged at a rate of about five to six times the rated charge capacity of the battery.

127. The process of claim 123, wherein the battery is a nickel-based secondary cell rechargeable battery.

128. The process of claim 127, wherein the battery is one of a group consisting of Nickel Cadmium and Nickel Metal Hydride type batteries and is discharged at a rate of about two times the rated charge capacity of the battery.

129. A method of aborting a battery charging process having alternating charging, discharging and wait periods, a battery charger providing a charge pulse during the charging period, a discharge pulse during the discharging period, and an electrically neutral stabilizing pause during the wait period, said aborting method comprising the steps of:

a) taking at least one measurement of the voltage level of the battery during the discharge period to arrive at a load voltage of the battery;

b) taking periodic measurements of the voltage level of the battery throughout the charging period to determine if a predetermined threshold voltage is exceeded;

c) aborting the charge pulse during the charging period if the threshold of step b) is exceeded and lengthening the wait period based upon the point in time at which the excessive voltage measurement was detected during the charging period;

d) at the end of the lengthened wait period of step c), partially discharging the battery and measuring the voltage level of the battery during the discharge period to determine if the measured load voltage exceeds the threshold voltage; and

discontinuing the charging process if the voltage measured in step d) exceeds the threshold voltage of step b) or continuing the charging process if the voltage measured in step d) does not exceed the threshold voltage of step b).

130. A method of detecting and recovering a battery from an abnormal condition to a normal charging condition during a charging process having a standard charging sequence comprising alternating charge, discharge, and rest periods, said method comprising the following steps:

a) measuring the voltage level of the battery during the charging process;

b) upon measuring an abnormal voltage condition substantially in excess of the rated voltage of the battery, interrupting the standard charging sequence and waiting a predetermined stabilization wait period;

c) applying a discharge pulse to the battery at the end of the stabilization wait period; and

d) measuring the voltage at the end of the discharge pulse and

     1) returning to the standard charging sequence if the voltage measurement drops below the abnormal voltage condition or

     2) terminating the charging process if the voltage measurement remains an abnormal voltage condition.

131. The method of claim 130, wherein the stabilization wait period is about in the range of 1 to 5 seconds.

132. The method of claim 130, wherein the battery is a nickel-based secondary cell rechargeable battery.

133. The method of claim 132, wherein the battery is one of a group consisting of Nickel Cadmium and Nickel Metal Hydride type batteries.

134. The method of claim 130, wherein the rated voltage of the battery is about 6 volts and the abnormal voltage condition is about equal to or greater than 15 volts.

135. A process of rapidly charging a battery by a battery charger having an input connected to a source of power, the battery charger providing alternating charge and discharge pulses to the battery, the charging process comprising the steps of:

a) applying a discharge pulse having a duration less than 10 milliseconds to partially discharge the battery substantially immediately prior to the charge pulse to lower the impedance and the voltage of the battery prior to the charge pulse being delivered to the battery;

b) after partially discharging the battery, supplying the charge pulse to the battery, the charge delivered to the battery during the charge pulse being greater than the charge drained from the battery during the discharge pulse of step a), and starting the charge pulse close enough in tine to the discharge pulse so that the voltage of the battery does not drift upwards a significant amount with respect to the loaded battery voltage as measured at or near the end of the discharge pulse;

c) waiting a rest period after the charge pulse and prior to applying a subsequent discharge pulse to the battery to allow the battery to at least partially stabilize; and

d) repeating he above steps.

136. A process of rapidly charging a battery by a battery charger having an input connected to a source of power, the battery charger providing alternating charge and discharge pulses to the battery, the charging process comprising the steps of:

a) with the battery at a first voltage level, partially discharging the battery prior to the charge pulse to reduce the voltage of the battery to a second voltage level that is less than the first voltage level;

b) after partially discharging the battery, supplying the charge pulse to the battery, the charge delivered to the battery during the charge pulse being greater than the charge drained from the battery during the discharge pulse of step a), and starting the charge pulse with the battery essentially at the reduced second voltage level;

c) waiting a rest period after the charge pulse and prior to applying a subsequent discharge pulse to the battery to allow the battery to at least partially stabilize; and

d) repeating the above steps.

137. The method of claim 136, wherein the charge pulse of step b) is applied immediately following the discharge pulse of step a).

138. The method of claim 136, wherein the charge pulse of step b) is applied within 4 milliseconds of the discharge pulse of step a).

139. A method of minimizing heat gain experienced by a rechargeable battery during a charging process of a battery charger having an input connected to a source of power, the charging process providing alternating charge and discharge pulses to the battery, said method comprising the following steps:

a) with the battery at a first voltage level, applying a predetermined discharge pulse and reducing the voltage level of the battery from the first voltage level to a second voltage level;

b) applying a charge pulse substantially immediately after the discharge pulse with the battery essentially at the second voltage level at the beginning of the charge pulse, the charge pulse raising the battery voltage to a third voltage level greater than the first voltage level;

c) waiting a rest period after the charge pulse and prior to applying a subsequent discharge pulse to the battery to allow the battery to at least partially stabilize, the rest period being substantially shorter in duration than the charge pulse of step b) over the majority of the charging process; and

d) repeating the above steps.

140. The method of claim 139 further comprising the step of determining an optimum charge pulse duration based upon the relationship between the first, second, and third voltage levels so as to maximize the charge pulse duration and minimize the duration of the charge process.

141. The method of claim 140 further comprising the step of determining an optimum discharge pulse duration and magnitude based upon the relationship between the first, second, and third voltage levels so as to maximize the charge pulse duration and minimize the duration of the charge process.

142. A method of maximizing the charge delivered to a rechargeable battery while minimizing heat generation during the process of recharging the battery by a battery charger having an input connected to a source of power, the battery charger providing alternating charge and discharge pulses to the battery, said method comprising the following steps:

a) applying a predetermined discharge pulse having a duration and magnitude;

b) applying a charge pulse essentially immediately after terminating the discharge pulse;

c) matching the discharge pulse duration and magnitude with the charging pulse duration and magnitude so that the discharge pulse lowers the impedance of the battery to an optimum level to best match the predetermined charge pulse for optimum charging, whereby the charge pulse duration is lengthened to an optimum period while minimizing the total battery charge time;

d) waiting an electrically-neutral rest period after the charge pulse and prior to applying a subsequent discharge pulse to the battery to allow the battery to at least partially stabilize, the rest period being substantially shorter in duration than the charge period of step b) over the majority of the charging process; and

e) repeating the above steps.

143. A method of essentially eliminating heat generation during the process of recharging a battery by a battery charger having an input connected to a source of power, the battery charger providing alternating charge and discharge pulses to the battery, said method comprising the following steps:

a) applying a predetermined discharge pulse having a duration and magnitude;

b) applying a charge pulse essentially immediately after terminating the discharge pulse;

c) matching the discharge pulse duration and magnitude with the charging pulse duration and magnitude so that the discharge pulse lowers the impedance of the battery to an optimum level to best match the predetermined charge pulse for optimum charging, whereby the charge pulse is lengthened to an optimum period while minimizing the total battery charge time;

d) waiting an electrically-neutral rest period after the charge pulse and prior to applying a subsequent discharge pulse to the battery to allow the battery to at least partially stabilize, the rest period being substantially shorter in duration than the charge period of step b) over the majority of the charging process; and

e) repeating the above steps.