High frequency battery charger and method of operating same

• US 6,822,425 B2
• Filed: 10/15/2002
• Issued: 11/23/2004
• Est. Priority Date: 01/25/2002
• Status: Expired due to Term

• Current Assignee: Vector Products Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Vector Products Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Krieger, Michael, Randolph, Bruce, Vetitoe, Roy Scott
• Primary Examiner(s): Tso, Edward H.
• Assistant Examiner(s): LUK, LAWRENCE W
• Application Number:
  US10/270,391
• Publication Number:
  US 20030141845A1
• Time in Patent Office: 770 Days
• Field of Search: 320/139, 320/137, 320/106, 320/110, 320/140, 320/141, 320/155, 320/162, 363/24, 363/97, 307/64, 307/65, 324/98, 324/772
• US Class Current: 320/139
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/007 Regulation of charging or discharging current or voltage
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034

Abstract

A high frequency charger includes a charge circuit for charging a depleted battery and a boost circuit for jump-starting a vehicle. Two separate high frequency transformers are provided for the charge and boost circuits. A selector switch selectively activates at least one of the charging circuit and the boost circuit.

Claims

1. A high frequency charger, comprising:

high frequency transformer means;

a first switch switching the high frequency transformer means at a first frequency and producing a charging current for charging a battery;

a second switch switching the high frequency transformer means at a second frequency and producing a relatively high boost current compared to the charging current for jump-starting a vehicle; and

a selector switch for selectively activating at least one of the first switch and the second switch;

wherein the high frequency transformer means comprises;

a first high frequency transformer for providing the charging current; and

a second high frequency transformer, separate from the first high frequency transformer, for providing the boost current.

2. The charger of claim 1, wherein the first switch switches the first high frequency transformer and the second switch switches the second high frequency transformer.

3. The charger of claim 2, further comprising:

a first controller providing a driving signal to the first switch; and

a second controller providing a driving signal to the second switch.

4. The charger of claim 3, wherein the selector switch is coupled to the first and second controllers for selectively activating at least one of the first and second controllers.

5. The charger of claim 4, wherein at least a portion of the high frequency transformer means and the first switch form a charging circuit, wherein the charging circuit has a charge mode and a pulse mode and further comprising a selector coupled to the first controller for selecting between the charge mode and the pulse mode.

6. The charger of claim 5, further comprising an enable circuit coupled to the selector that selectively enables and disables the first controller at a predetermined rate when the pulse mode is selected.

7. The charger of claim 3, further comprising a feedback circuit for being connected between the battery and the first controller for adjusting a duty cycle of the driving signal based on charging parameters of the battery.

8. The charger of claim 3, further comprising a control circuit coupled to the first controller for setting a duty cycle of the driving signal of the first controller.

9. The charger of claim 8, wherein the control circuit setting a duty cycle comprises:

an integrated circuit; and

at least two reference voltage circuits developing a reference voltage and coupled between the integrated circuit and the first controller, wherein the integrated circuit selectively enables at least one of the reference voltage circuits.

10. The charger of claim 9, wherein the integrated circuit comprises a counter.

11. The charger of claim 10, wherein each of the reference voltage circuits includes a switch that can be opened and closed in dependence on an output from the counter.

12. The charger of claim 8, wherein the control circuit setting a duty cycle comprises a voltage divider network dividing a voltage applied to a reference voltage input of the first controller and a control input of the first controller, wherein the duty cycle varies based on a percentage of the reference voltage applied to the control input.

13. The charger of claim 1, further comprising:

a filter coupled to the high frequency transformer means for passing a DC voltage signal to the high frequency transformer means.

14. A high frequency charger, comprising:

high frequency transformer means;

a first switch switching the high frequency transformer means at a first frequency and producing a charging current for charging a battery;

a second switch switching the high frequency transformer means at a second frequency and producing a relatively high boost current compared to the charging current for jump-starting a vehicle;

a selector switch for selectively activating at least one of the first switch and the second switch; and

at least one filter coupled to the output of the high frequency transformer means for passing a DC voltage signal to a charger output.

15. The charger of claim 14, further comprising:

a pair of connectors coupled to the at least one filter and adapted for connection to a battery;

at least one switch coupled in between one of the connectors and the at least one filter;

a polarity detection circuit coupled to the connectors for determining a polarity between the connectors and providing a polarity signal representing the polarity; and

a microprocessor receiving the polarity signal and generating a signal for opening or closing the at least one switch in dependence on the polarity signal.

16. The charger of claim 15, wherein the polarity detection circuit includes an opto-isolator.

17. The charger of claim 15, wherein the at least one switch includes a transistor.

18. The charger of claim 15, further comprising means for detecting disconnection of the connectors from the battery and opening the at least one switch when disconnection is detected.

19. A high frequency charger, comprising:

high frequency transformer means;

a first switch switching the high frequency transformer means at a first frequency and producing a charging current for charging a battery;

a second switch switching the high frequency transformer means at a second frequency and producing a relatively high boost current compared to the charging current for jump-starting a vehicle;

a selector switch for selectively activating at least one of the first switch and the second switch; and

means coupled to the first switch for alternatingly enabling the first switch to switch the high frequency transformer means at the first frequency and disabling the first switch from switching the high frequency transformer means;

wherein at least a portion of the high frequency transformer means and the first switch form a charging circuit, wherein the charging circuit has a charge mode and a pulse mode.

20. The charger of claim 19, wherein, in the pulse mode, the DC output signal of the charging circuit is a series of pulses.

21. The charger of claim 20, wherein the series of pulses has a rise time of less than 100 volts per microsecond.

22. The charger of claim 20, wherein the series of pulses has a frequency of about one pulse per second.

23. The charger of claim 19, further comprising means for selectively activating one of the charge mode and the pulse mode.

24. A high frequency charger, comprising:

high frequency transformer means;

a first switch switching the high frequency transformer means at a first frequency and producing a charging current for charging a battery;

a second switch switching the high frequency transformer means at a second frequency and producing a relatively high boost current compared to the charging current for jump-starting a vehicle; and

a selector switch for selectively activating at least one of the first switch and the second switch, wherein the boost current from the high frequency transformer means has a current of about 25-300 amps.

25. A high frequency charger, comprising:

high frequency transformer means;

a first switch switching the high frequency transformer means at a first frequency and producing a charging current for charging a battery;

a second switch switching the high frequency transformer means at a second frequency and producing a relatively high boost current compared to the charging current for jump-starting a vehicle; and

a selector switch for selectively activating at least one of the first switch and the second switch, wherein the boost current from the high frequency transformer means has a duration of about 3-35 seconds.

26. A high frequency charger, comprising:

high frequency transformer means;

a first switch switching the high frequency transformer means at a first frequency and producing a charging current for charging a battery;

a second switch switching the high frequency transformer means at a second frequency and producing a relatively high boost current compared to the charging current for jump-starting a vehicle;

a selector switch for selectively activating at least one of the first switch and the second switch;

a computer for controlling the operation of the first and second switches;

a display coupled to the computer for displaying an output from the computer, and

input means coupled to the computer for permitting a user to select a mode of operation.

27. The charger of claim 26, further comprising:

means for detecting at least one of a voltage and a current at an interface of the charger with a battery; and

a feedback circuit for feeding at least one of the detected voltage and current to the computer.

28. The charger of claim 27, wherein the means for detecting comprises an opto-isolator for producing a voltage representing the voltage of the battery while it is being charged by the charging current.

29. A high frequency charger, comprising:

high frequency transformer means;

a first switch switching the high frequency transformer means at a first frequency and producing a charging current for charging a battery;

a second switch switching the high frequency transformer means at a second frequency and producing a relatively high boost current compared to the charging current for jump-starting a vehicle;

a selector switch for selectively activating at least one of the first switch and the second switch;

means for testing for at least one fault; and

a display for displaying an alphanumeric fault code.

30. A high frequency charger, comprising:

high frequency transformer means;

a first switch switching the high frequency transformer means at a first frequency and producing a charging current for charging a battery;

a second switch switching the high frequency transformer means at a second frequency and producing a relatively high boost current compared to the charging current for jump-starting a vehicle;

a selector switch for selectively activating at least one of the first switch and the second switch;

a computer for controlling the operation of the first and second switches, wherein at least a portion of the high frequency transformer means and the first switch form a charging circuit, wherein the charging circuit has a charge mode and a pulse mode, and further comprising means for selectively activating one of the charge mode and the pulse mode; and

a computer-readable information storage medium, the computer-readable information storage medium storing computer-readable program code for causing the computer to perform the steps of;

detecting a selected of mode of operation; and

when a pulse mode is selected;

a) generating a driving signal for the first switch for a first period of time;

b) disabling the first switch for a second period of time; and

c) returning to step a).

31. A high frequency charger for charging a battery, comprising:

a charge circuit including a high frequency transformer;

a switching configuration to switch the high frequency transformer to produce a charging current to charge the battery, and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current;

a filter coupled to the high frequency transformer for passing a DC voltage signal;

means for measuring the charging current of the battery;

means for determining an amount of time the battery has been charging;

means for measuring a voltage of the battery; and

means for detecting at least an overtime fault, wherein the overtime fault is detected when the charging current is greater than a predetermined current, the battery has been charging longer than a predetermined amount of time, and the voltage of the battery is less than or equal to a predetermined voltage.

32. The charger of claim 31, wherein the predetermined current is about 2 amps, the predetermined time is about 18 hours, and the predetermined voltage is about 12 volts.

33. A high frequency charger for charging a battery, comprising:

a charge circuit including a high frequency transformer;

a switching configuration to switch the high frequency transformer to produce a charging current to charge the battery, and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current;

a filter coupled to the high frequency transformer for passing a DC voltage signal;

means for measuring at least one of a charging current of the battery, an amount of time the battery has been charging and a voltage of the battery;

means for detecting at least one of an overtime fault, a shorted cell fault, a bad battery fault, and an open cell fault based on at least one of the charging current, the charging time, and the battery voltage; and

a display that visually indicates at least one of the faults.

34. A high frequency charger for charging a battery, comprising:

a charge circuit including a high frequency transformer,

a switching configuration to switch the high frequency transformer to produce a charging current to charge the battery, and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current

a filter coupled to the high frequency transformer for passing a DC voltage signal;

means for determining an amount of time the battery has been charging;

means for measuring a voltage of the battery; and

means for detecting at least a shorted cell battery fault, wherein the shorted cell battery fault is detected when after a predetermined amount of time the battery voltage is less than or equal to a predetermined voltage.

35. The charger claim 34, wherein the predetermined time is about 1 hour, and the predetermined voltage is about 11 volts.

36. A high frequency charger for charging a battery, comprising:

a charge circuit including a high frequency transformer;

a switching configuration to switch the high frequency transformer to produce a charging current to charge the battery, and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current;

a filter coupled to the high frequency transformer for passing a DC voltage signal;

means for measuring a voltage of the battery; and

means for detecting at least a bad battery fault, wherein the bad battery fault is detected when no battery voltage is measured by the means for measuring.

37. A high frequency charger for charging a battery, comprising:

a charge circuit including a high frequency transformer;

a switching configuration to switch the high frequency transformer to produce a charging current to charge the battery, and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current;

a filter coupled to the high frequency transformer for passing a DC voltage signal;

means for measuring a charging current of the battery;

means for determining an amount of time the battery has been charging;

means for detecting an open cell battery fault, wherein the open cell battery fault is detected when the charging current is less than a predetermined current after the battery has been charging longer than a predetermined amount of time.

38. A high frequency charger, comprising:

a charging circuit including a high frequency transformer for producing a DC output signal;

a switching configuration to switch the high frequency transformer to produce a charging current to charge the battery, and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current;

a controller providing a high frequency driving signal to the switching configuration; and

an enable circuit that selectively enables and disables the controller at a predetermined rate for producing a series of DC pulses as the DC output signal, wherein the series of pulses has a rise time of less than 100 volts per microsecond.

39. A high frequency charger, comprising:

a charging circuit including a high frequency transformer for producing a DC output signal;

a switching configuration to switch the high frequency transformer to produce a charging current to charge the battery, and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current;

a controller providing a high frequency driving signal to the switching configuration; and

an enable circuit that selectively enables and disables the controller at a predetermined rate for producing a series of DC pulses as the DC output signal, wherein the series of pulses has a frequency of about one pulse per second.

40. A charger, comprising:

a charging circuit including a high frequency transformer for producing a DC charging signal;

a switching configuration to switch the high frequency transformer to produce a charging current to charge the battery, and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current;

first means for providing a driving signal to the switch that alternatingly turns the switch on and off at the high frequency; and

second means for selectively enabling and disabling the first means, whereby the DC charging signal comprises a series of DC pulses, wherein the series of pulses has a rise time of less than 100 volts per microsecond.

41. A charger, comprising:

a charging circuit including a high frequency transformer for producing a DC charging signal;

a switching configuration to switch the high frequency transformer to produce a charging current to charge the battery, and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current;

first means for providing a driving signal to the switch that alternatingly turns the switch on and off at the high frequency; and

second means for selectively enabling and disabling the first means, whereby the DC charging signal comprises a series of DC pulses and the series of pulses has a frequency of about one pulse per second.

42. A high frequency battery charger for charging a battery, comprising:

a charging circuit including a high frequency transformer for producing a DC output signal;

a switching configuration to switch the high frequency transformer to produce a charging current to charge the battery, and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current;

a controller providing a high frequency driving signal to the switching configuration;

measuring circuitry for measuring at least one of a voltage and a charging current at the battery; and

a processor to calculate diagnostics based on at least one of the voltage and current, wherein the diagnostics include at least one of an overtime fault, a shorted cell fault, a bad battery fault, and an open cell fault.

43. The charger of claim 42, wherein the processor determines a charging time of the battery.

44. The charger of claim 43, wherein the processor detects the overtime fault when the charging current is greater than a predetermined current after the battery has been charging longer than a predetermined amount of time.

45. The charger of claim 43, wherein the processor detects the shorted cell battery fault when after a predetermined amount of time the battery voltage is less than or equal to a predetermined voltage.

46. The charger of claim 43, wherein the processor detects the bad battery fault when no battery voltage is measured.

47. The charger of claim 43, wherein the processor detects the open cell battery fault when the current is less than a predetermined current after the battery has been charging more a predetermined amount.

48. A high frequency charger, comprising:

a high frequency transformer;

a switching configuration to switch the high frequency transformer to produce a charging current for charging a battery and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current; and

a controller providing a high frequency driving signal to the switching configuration, wherein the boost current is sufficient to jump start a vehicle.

49. The high frequency charger of claim 48, wherein the controller provides a pulse width modulated driving signal.

50. The high frequency charger of claim 48, further comprising measuring circuitry to measure at least one of a voltage and a current at the battery.

51. The high frequency charger of claim 50, further comprising a computer coupled to the measuring circuitry to calculate at least one diagnostic based on at least one of the measured voltage or current.

52. The high frequency charger of claim 48, further comprising a selector switch coupled to the controller for selecting one of (1) a charge mode in which the high frequency transformer is switched to produce the charging current and (2) a boost mode in which the high frequency transformer is switched to produce the boost current.

53. A high frequency charger, comprising:

a high frequency transformer;

a switching configuration to switch the high frequency transformer to produce a charging current for charging a battery and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current; and

a controller providing a high frequency driving signal to the switching configuration, wherein the boost current from the at least one high frequency transformer has a current of about 25-300 amps.

54. A high frequency charger, comprising:

a high frequency transformer;

a switching configuration to switch the high frequency transformer to produce a charging current for charging a battery and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current;

a controller providing a high frequency driving signal to the switching configuration;

connectors for coupling an output of the at least one high frequency transformer to the battery; and

a polarity protection circuit to allow current to flow through the connectors and to the battery only when the connectors are coupled to the battery with a correct polarity.

55. The high frequency charger of claim 54, wherein the polarity protection circuit is coupled to the connectors for determining a polarity between the connectors and provides a polarity signal;

and

a switch coupled to at least one of the connectors and being opened or closed in dependence on the polarity signal.

56. A high frequency charger, comprising:

a high frequency transformer;

a switching configuration to switch the high frequency transformer to produce a charging current for charging a battery and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current; and

a controller providing a high frequency driving signal to the switching configuration, wherein the boost current from the high frequency transformer has a duration of about 3-35 seconds.

57. A high frequency charger, comprising:

a high frequency transformer;

a switching configuration to switch the high frequency transformer to produce a charging current for charging a battery and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current;

a controller providing a high frequency driving signal to the switching configuration;

connectors adapted to be connected to the battery;

circuitry coupled to the connectors and operative to detect a fault with the battery; and

a display for indicating the detected fault.

58. The high frequency charger of claim 57, further comprising an alternator tester coupled to the connectors and producing an alternator fault signal.

59. The high frequency charger of claim 58, wherein the alternator tester further comprises:

circuitry operative to detect a rapid rise in voltage after a vehicle with the battery has been started and producing the alternator fault signal in the absence of the rapid rise in voltage; and

an indicator coupled to the circuitry for providing an indication that the vehicle'"'"'s alternator is not working properly in response to the alternator fault signal.

60. The high frequency charger of claim 57, further comprising circuitry coupled to the connectors and operative to desulfate the battery.

61. The high frequency charger of claim 57, wherein the fault includes at least one of an overtime fault, a shorted cell fault, a bad battery fault, and an open cell fault.

62. A high frequency charger, comprising:

a high frequency transformer;

a switching configuration to switch the high frequency transformer to produce a charging current for charging a battery and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current; and

a controller providing a high frequency driving signal to the switching configuration, wherein the switching configuration comprises;

a first switch switching the high frequency transformer to produce the charging current for charging the battery;

a second switch switching the high frequency transformer to produce the relatively high boost current.

63. The high frequency charger of claim 62, wherein the first switch is switched at a first frequency and the second switch is switched at a second frequency.

64. A high frequency charger comprising:

a single high frequency transformer;

a switching configuration to switch the single high frequency transformer to produce a charging current for charging a battery and to switch the single high frequency transformer to produce a relatively high boost current compared to the charging current; and

a controller providing a high frequency driving signal to the switching configuration.

65. A high frequency charger, comprising:

a high frequency transformer;

a switching configuration to switch the high frequency transformer to produce a charging current for charging a battery and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current; and

a controller providing a high frequency driving signal to the switching configuration;

wherein the high frequency transformer comprises;

a first high frequency transformer for providing the charging current; and

a second high frequency transformer, separate from the first high frequency transformer, for providing the relatively high boost current.

66. A high frequency charger, comprising:

a high frequency transformer;

a switching configuration to switch the high frequency transformer to produce a charging current for charging a battery and to switch the high frequency transformer to produce a relatively high boost current compared to the charging current;

a controller providing a high frequency driving signal to the switching configuration; and

a microprocessor coupled to the controller to control the controller to provide the driving signal to switch the switching configuration to produce the charging current or the relatively high boost current.

67. A charger, comprising:

a high frequency transformer having an input coupled to a DC input and an output for producing a DC output;

battery connectors coupled to the output of the high frequency transformer for supplying the DC output to a battery in a vehicle having an alternator electrically connected to the battery;

a switch circuit to switch the high frequency transformer;

a controller coupled to the switch circuit to drive the switch circuit at high frequency;

measuring circuitry coupled to the battery connectors to determine at least a voltage at the battery after the vehicle is started;

a processor coupled to the measuring circuitry to perform an alternator test for detecting an indication of alternator operation in dependence on at least the voltage at the battery; and

a display coupled to the processor to indicate at least one of the voltage of the battery and the indication of detected alternator operation, wherein an alternator fault is produced in the absence of a rise in voltage at the battery immediately after the vehicle is started.

68. The charger of claim 67, further comprising a feedback circuit coupled between the battery and the processor for adjusting a driving signal based on charging parameters of the battery.

69. A charger, comprising:

a high frequency transformer having an input coupled to a DC input and an output for producing a DC output;

battery connectors coupled to the output of the high frequency transformer for supplying the DC output to a battery in a vehicle having an alternator electrically connected to the battery;

a switch circuit to switch the high frequency transformer;

a controller coupled to the switch circuit to drive the switch circuit at high frequency;

measuring circuitry coupled to the battery connectors to determine at least a voltage at the battery after the vehicle is started;

a processor coupled to the measuring circuitry to perform an alternator test for detecting an indication of alternator operation in dependence on at least the voltage at the battery; and

a display coupled to the processor to indicate at least one of the voltage of the battery and the indication of detected alternator operation.

70. A charger, comprising:

a high frequency transformer having an input coupled to a DC input and an output for producing a DC output;

battery connectors coupled to the output of the high frequency transformer for supplying the DC output to a battery in a vehicle having an alternator electrically connected to the battery;

a switch circuit to switch the high frequency transformer;

a controller coupled to the switch circuit to drive the switch circuit at high frequency;

measuring circuitry coupled to the battery connectors to determine at least a voltage at the battery after the vehicle is started;

a controller coupled to the switch circuit to drive the switch circuit at high frequency;

measuring circuitry to determine at least a voltage of the battery;

a processor coupled to the measuring circuitry to perform an alternator test for detecting an indication of alternator operation in dependence on at least the voltage at the battery;

a display coupled to the processor to indicate at least one of the voltage of the battery and the indication of detected alternator operation; and

a polarity protection circuit coupled to the battery connectors to detect a polarity between the battery connectors when connected to the battery and to allow power to be supplied to the battery only when correct polarity is established.

71. A charger, comprising:

a high frequency transformer having an input coupled to a DC input and an output for producing a DC output;

battery connectors coupled to the output of the high frequency transformer for supplying the DC output to a battery in a vehicle having an alternator electrically connected to the battery;

a switch circuit to switch the high frequency transformer;

a controller coupled to the switch circuit to drive the switch circuit at high frequency;

measuring circuitry coupled to the battery connectors to determine at least a voltage at the battery after the vehicle is started;

a processor coupled to the measuring circuitry to perform an alternator test for detecting an indication of alternator operation in dependence on at least the voltage at the battery;

a display coupled to the processor to indicate at least one of the voltage of the battery and the indication of detected alternator operation; and

circuitry responsive to the processor that is operative to desulfate the battery.

72. A charger, comprising:

at least one high frequency transformer having an input coupled to a DC input and an output for producing a DC output;

battery connectors coupled to the output of the at least one high frequency transformer for supplying the DC output to a battery in a vehicle;

a switch circuit to switch the at least one high frequency transformer;

a controller coupled to the switch circuit to drive the switch circuit at high frequency;

measuring circuitry to determine at least a voltage of the battery;

a processor coupled to the measuring circuitry to perform an alternator test for detecting an indication of alternator operation in dependence on at least the voltage at the battery; and

a display coupled to the processor to indicate at least one of the voltage of the battery and the indication of detected alternator operation, wherein the switch circuit is operative to switch the at least one high frequency transformer to produce the DC output as a charging current for charging the battery and operative to switch the at least one high frequency transformer to produce the DC output as a boost current to jump-start the vehicle.

73. A charger, comprising:

a high frequency transformer having an input coupled to a DC input and an output

for producing a DC output;

battery connectors coupled to the output of one high frequency transformer for supplying the DC output to a battery in a vehicle;

a switch circuit to switch the at least one high frequency transformer;

a controller coupled to the switch circuit to drive the switch circuit at high frequency;

measuring circuitry to determine at least a voltage of the battery;

a processor coupled to the measuring circuitry, the processor adapted for performing an alternator test for detecting an indication of alternator operation in dependence on at least the voltage at the battery; and

a display coupled to the processor to indicate at least one of the voltage of the battery and the indication of detected alternator operation, wherein the charger has a

charge mode in which the at least one high frequency transformer is switched to produce a charging current and a boost mode in which the at least one high frequency transformer is switched to produce a boost current, and the charger further includes a selector switch responsive to user input to select different modes of operation for the charger and to provide a signal to the processor, which then controls the controller based on the selected mode of operation.

74. A high frequency charger arrangement, comprising:

a high frequency transformer having an input coupled to a DC input and an output for producing a DC output;

battery connectors coupled to the output of the high frequency charger for supplying the DC output to a battery in a vehicle;

a selector switch to receive user input to select different modes of operation for the charger;

a switch configuration to switch high frequency transformer in one mode to produce the DC output as a charging current for charging a battery and in another mode to switch the high frequency transformer to produce the DC output as a relatively high boost current compared to the charging current;

a controller coupled to the switch configuration and to the selector switch to provide a driving signal to the switch configuration to drive the switch configuration based on the selected mode of operation;

measuring circuitry to determine at least one of a voltage of a battery, a current supplied to the battery or a voltage between the battery connectors;

a processor coupled to the measuring circuitry to perform fault detection at the battery and an alternator test for detecting an indication of alternator operation based on at least one of the voltage of the battery, the current supplied to the battery or the voltage between the battery connectors;

a display coupled to the processor to indicate at least one of the voltage of the battery, the voltage between the battery connectors, the detected fault, and a result of the alternator test;

a polarity protection circuit coupled to the battery connectors to detect a polarity of the battery and to allow power to be supplied to the battery only when correct polarity is established; and

circuitry responsive to the processor that is operative to desulfate the battery.

75. A high frequency charger, comprising:

a high frequency transformer configuration;

a switch to switch the high frequency transformer configuration to produce a charging current for charging a battery and to switch the high frequency transformer to produce a boost current that is relatively high compared to the charging current, the high frequency transformer configuration being operative to produce a series of DC pulses to be applied to the battery;

measuring circuitry to measure at least one of a voltage and a current at the battery; and

a controller coupled to the measuring circuitry and providing a high frequency driving signal to the switch based on at least one of the voltage and the current at the battery , wherein the charger operates in a charge mode in which a relatively continuous DC charging signal is output by the at least one high frequency transformer configuration and in a pulse mode in which the series of DC pulses is output by the at least one high frequency transformer configuration.

76. A high frequency charger, comprising:

a high frequency transformer configuration;

a switch to switch the high frequency transformer configuration to produce a charging current for charging a battery and to switch the high frequency transformer to produce a boost current that is relatively high compared to the charging current, the high frequency transformer configuration being operative to produce a series of DC pulses to be applied to the battery;

measuring circuitry to measure at least one of a voltage and a current at the battery; and

a controller coupled to the measuring circuitry and providing a high frequency driving signal to the switch based on at least one of the voltage and the current at the battery, wherein the series of pulses has a rise time of less than 100 volts per microsecond.

77. A high frequency charger, comprising:

a high frequency transformer configuration;

a switch to switch the high frequency transformer configuration to produce a charging current for charging a battery and to switch the high frequency transformer to produce a boost current that is relatively high compared to the charging current, the high frequency transformer configuration being operative to produce a series of DC pulses to be applied to the battery;

measuring circuitry to measure at least one of a voltage and a current at the battery; and

a controller coupled to the measuring circuitry and providing a high frequency driving signal to the switch based on at least one of the voltage and the current at the battery, wherein the series of pulses has a frequency of about one pulse per second.

78. A high frequency charger, comprising:

a high frequency transformer configuration;

a switch to switch the high frequency transformer configuration to produce a charging current for charging a battery and to switch the high frequency transformer to produce a boost current that is relatively high compared to the charging current, the high frequency transformer configuration being operative to produce a series of DC pulses to be applied to the battery;

measuring circuitry to measure at least one of a voltage and a current at the battery;

a controller coupled to the measuring circuitry and providing a high frequency driving signal to the switch based on at least one of the voltage and the current at the battery; and

a microprocessor coupled to the controller to selectively enable and inhibit the controller to produce the driving signal.

79. A high frequency charger, comprising:

a high frequency transformer configuration;

a switch to switch the high frequency transformer configuration to produce a charging current for charging a battery and to switch the high frequency transformer to produce a boost current that is relatively high compared to the charging current, the high frequency transformer configuration being operative to produce a series of DC pulses to be applied to the battery;

measuring circuitry to measure at least one of a voltage and a current at the battery;

a controller coupled to the measuring circuitry and providing a high frequency driving signal to the switch based on at least one of the voltage and the current at the battery; and

a microprocessor coupled to the controller to control the controller to vary a duty cycle of the driving signal.

80. A method comprising:

producing both a charge current and a boost current for a battery using high frequency switching of a DC energy source through a high frequency transformer;

delivering one or both of the charge and boost currents to a battery, wherein the boost current is relatively greater than the charge current.

81. A method comprising:

producing both a charge current and a boost current for a battery using high frequency switching of a DC energy source through a high frequency transformer; and

delivering one or both of the charge and boost currents to a battery, wherein the boost current is relatively greater than the charge current, wherein the boost current is in a range of about 25 amps to about 300 amps.

82. A high frequency charger, comprising:

a high frequency transformer;

a first switch switching the high frequency transformer at a first frequency and producing a charging current for charging a battery;

a second switch switching the high frequency transformer at a second frequency and producing a relatively high boost current compared to the charging current for jump-starting a vehicle; and

a selector switch for selectively activating at least one of the first switch and the second switch, wherein the boost current from the high frequency transformer has a current of about 25-300 amps.

83. A high frequency charger, comprising:

a high frequency transformer;

a first switch switching the high frequency transformer at a first frequency and producing a charging current for charging a battery;

a second switch switching the high frequency transformer at a second frequency and producing a relatively high boost current compared to the charging current for jump-starting a vehicle;

a selector switch for selectively activating at least one of the first switch and the second switch;

at least one filter coupled to the output of the high frequency transformer for passing a DC voltage signal to a charger output;

a pair of connectors coupled to the at least one filter and adapted for connection to the battery;

at least one switch coupled in between one of the connectors and the at least one filter;

a polarity detection circuit coupled to the connectors for determining a polarity between the connectors and providing a polarity signal representing the polarity; and

a microprocessor receiving the polarity signal and generating a signal for opening or closing the at least one switch in dependence on the polarity signal.

84. The charger of claim 83, further comprising:

a display coupled to the computer for displaying output from the computer; and

input means coupled to the computer for permitting a user to select a mode of operation.

85. A high frequency charger, comprising:

a high frequency transformer;

a first switch switching the high frequency transformer at a first frequency and producing a charging current for charging a battery;

a second switch switching the high frequency transformer at a second frequency and producing a relatively high boost current compared to the charging current for jump-starting a vehicle;

a selector switch for selectively activating at least one of the first switch and the second switch; and

a computer for controlling the operation of the first and second switches.

86. A high frequency charger, comprising:

a high frequency transformer;

a first switch switching the high frequency transformer at a first frequency and producing a charging current for charging a battery;

a second switch switching the high frequency transformer at a second frequency and producing a relatively high boost current compared to the charging current for jump-starting a vehicle;

a selector switch for selectively activating at least one of the first switch and the second switch;

means for testing for at least one fault; and

a display for displaying an alphanumeric fault code.