System and method for charging batteries

• US 20050088144A1
• Filed: 08/24/2004
• Published: 04/28/2005
• Est. Priority Date: 10/23/2003
• Status: Active Grant

• Current Assignee: Schumacher Electric Corporation
• Original Assignee: Schumacher Electric Corporation
• Inventors: Johnson, Thomas Finis, Pacholok, David R., Chen, Xiao Ping
• Granted Patent: US 7,528,579 B2
• Time in Patent Office: Days
• US Class Current: 320/131
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters

Abstract

A high frequency battery charger includes a converter, drive logic, and control logic. The converter transforms a DC voltage into a high frequency AC voltage. The drive logic controls a conversion of the high frequency AC voltage through a train of pulses. The control logic adjusts the output of the converter to maximize a charging cycle of a battery. The method of transforming an AC input into a direct current output used to charge a rechargeable battery includes transforming an AC input into a first DC output; transforming the first DC output into a high frequency AC output; transforming the high frequency AC output into a second DC output; and passing a charging current to an external load when the load is correctly connected to an output.

Claims

1. A high frequency battery charger, comprising:

a converter that transforms a DC voltage into a high frequency AC voltage;

a drive logic that controls a conversion of the high frequency AC voltage by producing a train of pulses; and

control logic that adjusts an output of the converter to maximize a charging cycle of a battery.

2. The high frequency battery charger of claim 1 wherein the converter comprises a high frequency transformer.

3. The high frequency transformer of claim 2 further including a switch for coupling a source to the converter.

4. The high frequency transformer of claim 3 further comprising a second and a third switch that provide a current path to a primary winding, the second and third switch being directly connected to the primary winding.

5. The high frequency battery charger of claim 1 wherein the control logic is programmed to provide a bulk charge, an absorption charge, a maintenance charge, a float mode monitoring and a desulfation charge.

6. The high frequency battery charger of claim 5 wherein the desulfation charge comprise a series of pulse charges that reverses a build up of contaminants on a load'"'"'s electrodes.

7. The high frequency battery charger of claim 5 wherein the desulfation charge comprise a series of pulse charges or a high charging voltage that reverses a build up of contaminants on a load'"'"'s electrodes.

8. The high frequency battery charger of claim 1 wherein the high frequency charger includes a sensor that provides spark resistant protection in a reverse polarity connection.

9. The high frequency battery charger of claim 1 further comprising a switch coupled to the control logic for passing a charging current to a load only when the load is correctly connected to output charging connectors.

10. The high frequency battery charger of claim 1 further including a meter that measures a charging current.

11. The high frequency battery charger of claim 1 wherein the converter and driver are optically isolated from the control logic.

12. The high frequency battery charger of claim 1 further comprising a second converter that transforms the high frequency AC voltage into a second DC voltage.

13. The high frequency battery charger of claim 12 wherein the second converter comprises a bridge rectifier.

14. The high frequency battery charger of claim 1 further comprising a display coupled to the control logic.

15. The high frequency battery charger of claim 1 further comprising a sensor that controls the drive logic by monitoring a current flowing through a high frequency transformer.

16. The high frequency battery charger of claim 15 wherein the sensor controls the drive logic by monitoring the current flowing through a primary winding of the high frequency transformer.

17. The high frequency batter charger of claim 15 further comprising a synchronous converter that transforms the high frequency AC voltage into a low frequency direct current.

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

a first converter that transforms an alternating current into a into a low frequency direct current, and then into a high frequency alternating output current;

a synchronous converter that transforms the high frequency alternating output current to a second low frequency direct current;

a drive logic that controls a transformation of high frequency alternating output current into a second low frequency direct current signal; and

a processor that adjusts a level of charging current of the synchronous converter that passes onto a load.

19. The high frequency battery charger of claim 18 wherein the first converter comprises a high frequency transformer.

20. The high frequency transformer of claim 19 further including a switch for coupling the alternating current to the first converter.

21. The high frequency transformer of claim 20 further comprising a second and a third switch that provide a current path to a primary winding of the high frequency transformer, the second and third switch being directly connected to the primary winding.

22. The high frequency battery charger of claim 18 wherein the processor is programmed to provide a bulk charge, an absorption charge.

23. The high frequency battery charger of claim 18 wherein the equalization charge comprise a series of pulse charges that reverses a build up of contaminants on a load'"'"'s electrodes.

24. The high frequency battery charger of claim 18 wherein the high frequency charger includes a sensor that provides a spark resistant protection in a reverse polarity connection of the load.

25. The high frequency battery charger of claim 18 further comprising a switch coupled to the processor for passing a charging current to the load only when the load is correctly connected to output charging connectors.

26. The high frequency battery charger of claim 18 further including a meter coupled to the processor.

27. The high frequency battery charger of claim 18 wherein the first converter and drive logic are optically isolated from the processor.

28. The high frequency battery charger of claim 18 wherein the first converter comprises a bridge rectifier.

29. The high frequency battery charger of claim 18 further comprising a display coupled to the processor.

30. The high frequency battery charger of claim 18 further comprising a sensor that controls the drive logic by monitoring a current flowing through a high frequency transformer.

31. The high frequency battery charger of claim 30 wherein the sensor controls the drive logic by monitoring the current flowing through a primary winding of the high frequency transformer.

32. The high frequency battery charger of claim 30 wherein the charging current is a pulsating current.

33. The high frequency battery charger of claim 18 further comprising a temperature sensor coupled to the processor, an output of the temperature sensor being used to adjust the level of charging current that passes to the load.

34. The high frequency battery charger of claim 18 further comprising a medium that may be read by the processor to detect a defective battery.

35. A method of transforming an AC input into a direct current output used to charge a rechargeable battery comprising:

transforming an AC input into a first DC output;

transforming the first DC output into a high frequency AC output;

transforming the high frequency AC output into a second DC output; and

passing a charging current to a load only when the load is correctly connected to an output of a charging connector.

36. The method of claim 35 wherein the act of transforming the first DC input into a high frequency AC output comprises actuating a plurality switches coupled to a primary of a high frequency transformer.

37. The method of claim 35 further comprising the act of monitoring the charging current with a processor.

38. The method of claim 35 further comprising the act of providing a spark resistance when a load is connected in a reverse polarity.

39. The method of claim 35 wherein the act of passing the charging current comprises passing the charging current onto a battery only when the charging current is below a predetermined threshold.

40. The method of claim 35 wherein the charging current comprises a pulsating current.

41. A high frequency battery charger that responds to an actuation of a switch comprising:

a switch logic configured to display an actuation of a switch; and

a processor configured to process data contemporaneously with the actuation of the switch, wherein the processor is configured to enable a single state with each actuation of the switch.

42. The high frequency charger of claim 41 further comprising a battery coupled to the processor, wherein the processor compares a first average battery voltage measured during a first predetermined time period to a second average battery voltage measured during a second predetermined time period when detecting a disconnected battery condition.

43. The high frequency battery charger of claim 42 wherein the first predetermined time period comprises about two seconds and the second predetermined time period comprises about one quarter of a second.