Method and apparatus for charging a battery

• US 6,313,608 B1
• Filed: 05/22/2000
• Issued: 11/06/2001
• Est. Priority Date: 11/03/1997
• Status: Expired due to Term

• Current Assignee: Midtronics Incorporated
• Original Assignee: Midtronics Incorporated
• Inventors: Bertness, Kevin I., McShane, Stephen J., Varghese, Philip
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/575,627
• Time in Patent Office: 533 Days
• Field of Search: 320/132, 320/134, 320/136, 320/160, 320/162, 324/430, 324/432, 324/433
• US Class Current: 320/132
• CPC Class Codes: G01R 31/3647 for determining the ability of a battery to perform a critical function, e.g. cranking
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• CPC Class Codes: H02J 7/00041 in response to measured battery parameters, e.g. voltage, current or temperature profile
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: Y10S 320/21 State of charge of battery

Abstract

A battery charger includes a first pair of electrical connectors configured to couple to a positive terminal of the battery and a second pair of electrical connectors configured to couple to a negative terminal of the battery. The first pair and second pair of connectors forming Kelvin connections to the battery. A microprocessor is configured to selectively charge the battery and measure a dynamic parameter of the battery as a function of an AC signal applied to the battery.

Claims

1. An apparatus for charging a storage battery, comprising:

a first positive electrical connector to couple to a positive terminal of the battery and carry an electrical signal;

a second positive electrical connector to couple to the positive terminal of the battery and carry an electrical signal;

a first negative electrical connector to couple to a negative terminal of the battery and carry an electrical signal;

a second negative electrical connector to couple to the negative terminal of the battery and carry an electrical signal, at least one of the positive electrical connectors and at least one of the negative electrical connectors configured to charge the battery;

an AC source configured to selectively couple an AC signal to the battery through at least one of the positive electrical connectors and one of the negative electrical connectors;

a microprocessor configured to selectively charge the battery through at least one positive and negative electrical connector and measure a dynamic parameter of the battery as a function of the AC signal applied to the battery.

2. The apparatus of claim 1 wherein the first positive and first negative connectors carry a voltage signal, the second positive and second negative connectors carry a current signal and the dynamic parameter is a function of the voltage and current signals.

3. The apparatus of claim 1 wherein the AC signal comprises a charging signal.

4. The apparatus of claim 1 wherein the dynamic parameter is a function of battery conductance.

5. The apparatus of claim 1 wherein the microprocessor provides an output related to battery condition as a function of the measured dynamic parameter.

6. The apparatus of claim 5 wherein the output related to battery condition comprises battery cold cranking amps (CCA).

7. The apparatus of claim 4 wherein the cold cranking amp output is displayed in a graphical form.

9. The apparatus of claim 7 wherein the graph comprises a full/empty graph.

10. The apparatus of claim 1 including:

voltage measurement circuitry coupled to the first positive electrical connector and first negative electrical connector to responsively provide a measured voltage output related to a voltage between the first positive and first negative connectors; and

the microprocessor responsively provides the dynamic parameter as a function of the measured voltage output.

11. The apparatus of claim 1 including a memory to store a rating related to the battery in a fully charged condition and wherein the microprocessor provides a state of charge output as a function of the dynamic parameter output and the stored battery rating.

12. The apparatus of claim 11 wherein the state of charge output comprises a percentage.

13. The apparatus of claim 1 wherein the dynamic parameter is a ratio of a current through the battery and a voltage across the battery.

14. The apparatus of claim 1 including a charging source configured to provide a charging signal to the battery.

15. The apparatus of claim 14 wherein the charge signal from the charging source is responsive to the measured dynamic parameter to thereby control charging of the battery.

16. The apparatus of claim 11 including input circuitry adapted to receive an input related to battery rating for storage in the memory.

17. The apparatus of claim 16 wherein the input comprises a user input.

18. The apparatus of claim 16 wherein the input comprises selected from the group of inputs consisting of battery make, battery model, battery type, battery part number and battery rating.

19. The apparatus of claim 11 wherein the memory is adapted to store a cold cranking amp rating.

20. The apparatus of claim 1 wherein the microprocessor determines state of charge of the battery as a function of the dynamic parameter and the state of charge increases as battery impedance decreases.

21. The apparatus of claim 1 including a load resistance configured to remove surface charge from the battery prior to measuring the dynamic parameter.

22. The apparatus of claim 1 wherein the AC signal includes a stepped DC component.

23. The apparatus of claim 1 wherein the microprocessor provides an output indicative of a bad cell in the battery.

24. The apparatus of claim 1 including a parameter input and wherein the microprocessor provides a battery condition output as a function of the parameter input and the dynamic parameter.

25. The apparatus of claim 24 wherein the parameter input is received over a non-physical link.

26. The apparatus of claim 25 wherein the non-physical link is selected from the group consisting of IR, RF, and ultrasonic.

27. The apparatus of claim 24 wherein the parameter input comprises a CCA rating.

28. The apparatus of claim 24 wherein parameter input comprises a JIS rating.

29. The apparatus of claim 24 wherein the battery condition is selected from the group consisting of recovery of amp hours, reserve capacity, time to full charge and charge remaining.

30. The apparatus of claim 1 including an I/O port configured to couple to an external device.

31. The apparatus of claim 30 wherein the external device comprises a printer.

32. The apparatus of claim 30 wherein the external device comprises a storage device.

33. The apparatus of claim 30 wherein the external device comprises an automotive analysis device.

34. The apparatus of claim 30 wherein the external device comprises a battery tester.

35. The apparatus of claim 30 wherein the I/O port comprises a non-physical link.

36. The apparatus of claim 35 wherein the link comprises an infrared link.

37. The apparatus of claim 35 wherein the link comprises a radio frequency link.

38. The apparatus of claim 35 wherein the link comprises an ultrasonic link.

39. The apparatus of claim 1 including output circuitry adapted to provide an encrypted audit code.

40. The apparatus of claim 39 wherein the audit code includes a sequence code.

41. The apparatus of claim 39 wherein the audit code includes time information.

42. The apparatus of claim 39 wherein the audit code includes date information.

43. The apparatus of claim 39 wherein the audit code includes the dynamic parameter.

44. The apparatus of claim 39 wherein the audit code includes information related to a charging sequence performed on the battery.

45. The apparatus of claim 39 wherein the audit code includes battery condition information.

46. The apparatus of claim 39 wherein the audit code identifies an operator of the apparatus.

47. The apparatus of claim 1 wherein the dynamic parameter is a function of battery resistance.

48. The apparatus of claim 1 wherein the dynamic parameter is a function of battery impedance.

49. The apparatus of claim 1 wherein the dynamic parameter is a function of battery admittance.

50. The apparatus of claim 1 wherein the battery is charged in accordance with a battery charge profile and as a function of the dynamic parameter.

51. The apparatus of claim 1 wherein charging of the battery is suspended during measurement of the dynamic parameter.

52. The apparatus of claim 1 wherein the AC source comprises a resistive load selectively coupled across the terminals of the battery.

53. The apparatus of claim 1 including a differential amplifier coupled across the battery to measure a differential AC voltage developed in response to the AC signal.

54. The apparatus of claim 53 wherein the differential amplifier is coupled to the battery through capacitors.

55. The apparatus of claim 1 wherein the microprocessor provides an output indicating a good battery.

56. The apparatus of claim 1 wherein the microprocessor provides an output indicating the battery is good and should be recharged.

57. The apparatus of claim 1 wherein the microprocessor provides an output indicating the battery should be charged and retested.

58. The apparatus of claim 1 wherein the microprocessor determines an expected time to charge the battery as a function of the dynamic parameter.

59. The apparatus of claim 58 wherein the microprocessor perform an extended charge for a period longer than the predicted time to charge as a function of the dynamic parameter measured after the predicted time to charge has elapsed.

60. The apparatus of claim 58 wherein the predicted time to charge is a function of a look up table.

61. The apparatus of claim 1 wherein the microprocessor provides a replace battery output indicating the battery should be replaced.

84. The method of claim 1 including receiving a parameter input and providing a battery condition output as a function of the parameter input and the dynamic parameter.

85. The method of claim 84 wherein the parameter input is received over a non-physical link.

86. The method of claim 85 wherein the non-physical link is selected from the group consisting of IR, RF, and ultrasonic.

87. The method of claim 84 wherein the parameter input comprising a CCA rating.

88. The method of claim 84 wherein parameter input comprising a JIS rating.

89. The method of claim 84 wherein the battery condition is selected from the group consisting of recovery of amp hours, reserve capacity, time to full charge and charge remaining.

99. The method of claim 1 including outputting an audit code.

100. The method of claim 99 wherein the audit code includes a sequence code.

101. The method of claim 99 wherein the audit code includes time information.

102. The method of claim 99 wherein the audit code includes date information.

103. The method of claim 99 wherein the audit code includes the dynamic parameter.

104. The method of claim 99 wherein the audit code includes a charging sequence performed on the battery.

105. The method of claim 99 wherein the audit code includes battery condition.

106. The method of claim 99 wherein the audit code identifies an operator of the apparatus.

113. The method of claim 60 including amplifying a differential signal across the battery to measure a differential AC voltage developed in response to the AC signal.

117. The method of claim 1 including determining an expected time to charge the battery as a function of the dynamic parameter.

118. The method of claim 117 including performing an extended charge for a period longer than the predicted time to charge as a function of the dynamic parameter measured after the predicted time to charge has elapsed.

119. The method of claim 117 wherein the predicted time to charge is a function of a look up table.

8. The apparatus of the 7 wherein the graph comprises a bar graph.

62. A method of testing a storage battery while charging the storage battery, comprising:

coupling a first positive electrical connector to a positive terminal of the battery;

coupling a first negative electrical connector to a negative terminal of the battery;

coupling a second positive electrical connector to the positive terminal of the battery;

coupling a second negative electrical connector to the negative terminal of the battery;

applying a charging signal to the battery to thereby charge the storage battery while the first positive and negative and second positive and negative connectors are coupled to the battery;

measuring a dynamic parameter of the battery through the first positive, first negative and second positive and second negative connectors as a function of an applied AC signal; and

responsively controlling the charge signal as a function of the dynamic parameter.

63. The method of claim 62 wherein the charging signal includes an AC component and the dynamic parameter is determined as a function of the charge signal.

64. The method claim 62 wherein the first positive and first negative connectors carry a voltage signal, the second positive and second negative connectors carry a current signal and the dynamic parameter is a function of the voltage and current signals.

65. The method of claim 62 wherein the AC signal comprises the charging signal.

66. The method paratus of claim 62 wherein the dynamic parameter is a function of battery conductance.

67. The method of claim 62 including providing an output related to battery condition as a function of the measured dynamic parameter.

68. The method of claim 67 wherein the output related to battery condition comprises battery cold cranking amps (CCA).

69. The method of claim 67 including displaying the condition in a graphical form.

71. The method of claim 69 wherein the graph comprises a full/empty graph.

72. The method of claim 62 including:

measuring a voltage related to a voltage between the first positive and first negative connectors; and

providing the dynamic parameter as a function of the measured voltage.

73. The method of claim 62 including storing a battery rating related to the battery in a fully charged condition and wherein providing a state of charge output as a function of dynamic parameter output and the stored battery rating.

74. The method of claim 73 wherein the state of charge output comprises a percentage.

75. The method of claim 62 wherein the dynamic parameter output is a ratio of a current through the battery and voltage across the battery.

76. The method of claim 62 including receiving an input related to battery rating.

77. The method of claim 76 wherein the input is a user input.

78. The method of claim 76 wherein the input is selected from the group of inputs consisting of battery make, battery model, battery type, battery part number and battery rating.

79. The method of claim 73 wherein the battery rating comprises a cold cranking amp rating.

80. The method of claim 62 including determining state of charge of the battery as a function of the dynamic parameter and where the state of charge increases as battery impedance decreases.

81. The method of claim 62 including applying a load resistance to remove surface charge from the battery prior to measuring the dynamic parameter.

82. The method of claim 62 wherein the AC signal includes a stepped DC component.

83. The method of claim 62 including providing an output indicative of a bad cell in the battery.

90. The method of claim 62 including coupling to an external device through an I/O port.

91. The method of claim 90 wherein the external device comprises a printer.

92. The method of claim 90 wherein the external device comprises a storage device.

93. The method of claim 90 wherein the external device comprises an automotive analysis device.

94. The method of claim 90 wherein the external device comprises a battery tester.

95. The method of claim 90 wherein the I/O port comprises a non-physical link.

96. The method of claim 95 wherein the link comprises an infrared link.

97. The method of claim 95 wherein the link comprises a radio frequency link.

98. The method of claim 95 wherein the link comprises an ultrasonic link.

107. The method of claim 62 wherein the dynamic parameter is a function of battery resistance.

108. The method of claim 62 wherein the dynamic parameter is a function of battery impedance.

109. The method of claim 62 wherein the dynamic parameter is a function of battery admittance.

110. The method of claim 62 including charging the battery in accordance with a battery charge profile and as a function of the dynamic parameter.

111. The method of claim 62 including charging of the battery is during measurement of the dynamic parameter.

112. The method of claim 62 including selectively coupling a resistive load across the terminals of the battery to provide the AC signal.

114. The method of claim 62 including providing an output indicating a good battery.

115. The method of claim 62 including providing an output indicating the battery is good and should be recharged.

116. The method of claim 62 including providing an output indicating the battery should be charged and retested.

120. The method of claim 62 including providing a replace battery output indicating the battery should be replaced.

70. The method of the 69 wherein the graph comprises a bar graph.