Battery pack

• US 20080169788A1
• Filed: 01/14/2008
• Published: 07/17/2008
• Est. Priority Date: 01/12/2007
• Status: Active Grant

• Current Assignee: Koehler-Bright Star Incorporated (Berkshire Hathaway Incorporated)
• Original Assignee: Koehler-Bright Star Incorporated (Berkshire Hathaway Incorporated)
• Inventors: Dirsa, Mark, Bobbin, Joseph
• Granted Patent: US 8,729,851 B2
• Time in Patent Office: Days
• US Class Current: 320/135
• CPC Class Codes: F21V 21/084 Head fittings
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 50/213 adapted for cells having curved cross-section, e.g. round or elliptic H01M50/209, H01M50/216 take precedence
• CPC Class Codes: H01M 50/227 Organic material
• CPC Class Codes: H01M 50/242 adapted for protecting batteries against vibrations, collision impact or swelling
• CPC Class Codes: H01M 50/271 Lids or covers for the racks or secondary casings
• CPC Class Codes: H01M 50/284 with incorporated circuit boards, e.g. printed circuit boards [PCB]
• CPC Class Codes: H01M 50/296 characterised by terminals of battery packs terminals of batteries H01M50/543
• CPC Class Codes: H01M 50/574 Devices or arrangements for the interruption of current
• CPC Class Codes: H01M 50/588 outside the batteries, e.g. incorrect connections of terminals or busbars
• CPC Class Codes: H01M 50/591 Covers
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/00308 Overvoltage protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery pack features a shock-absorbing and sealed construction and an electronic control module that provides automatic recovery circuitry in the event of a short circuit in the load whereby the power is terminated and then restarted at a lower level so that removal of the short circuit may be detected. Full power is restored to the load when the short circuit is removed. In addition, the electronic control module of the battery pack uses the battery pack load, such as a cap lamp, to provide an indication of a low battery charge level. The electronic control module also provides a soft-start feature where the power provided to the bulb is ramped up to avoid current in-rush to the bulb during startup.

Claims

1. A battery pack comprising:

a. a housing;

b. a battery cell positioned within said housing;

c. a pair of terminals attached to said housing for providing power from said battery cell to a load;

d. an electronic control module positioned within said housing and in series between said pair of terminals and said battery cell; and

e. said electronic control module detecting when a fault condition exists in the load and, after terminating current flow from the battery cell to the terminals, providing a reduced current flow to the load while sensing the reduced current flow and restoring full current flow when sensing that the fault condition no longer exists in the load.

2. The battery pack of claim 1 wherein said electronic control module includes a transistor and a microprocessor and said microprocessor provides a reduced current flow to the load when the fault condition is present by pulsing the transistor.

3. The battery pack of claim 2 wherein the transistor is controlled by the microprocessor to subject the current to pulse width modulation.

4. The battery pack of claim 1 wherein the fault condition is a short circuit.

5. The battery pack of claim 1 wherein the load is a cap lamp.

6. The battery pack of claim 1 wherein said electronic control module includes a microprocessor.

7. The battery pack of claim 6 wherein the electronic control module includes an overload sensor circuit having an input that receives a sensed current flowing from the battery pack to the load and an output in communication with the microprocessor, said overload sensor circuit sending an indication to the microprocessor when the fault condition exists based on the sensed flow of current.

8. The battery pack of claim 7 wherein the overload sensor circuit includes an operational amplifier having an input receiving a sensed flow of current from the battery pack to the load and an output in communication with the microprocessor.

9. The battery pack of claim 1 wherein the battery cell is a Lithium-ion cell.

10. The battery pack of claim 1 wherein the electronic control module senses a current flowing from the battery pack to the load to detect when a fault condition exists.

11. A method of automatically restoring a flow of current to a load from a battery pack after a fault condition occurs in the load comprising the steps of:

a. sensing a flow of current to the load;

b. detecting when the fault condition occurs in the load; and

c. restoring a full flow of current to the load when the fault condition is removed.

12. The method of claim 11 further comprising the steps of:

a. terminating the flow of current to the load after detecting when the fault condition occurs;

b. providing a reduced flow of current to the load after the flow is terminated;

c. sensing the reduced flow of current to the load for removal of the fault condition.

13. The method of claim 12 wherein said reduced flow of current is provided by pulsing a transistor.

14. The method of claim 13 wherein the transistor is controlled by a microprocessor to subject the current to pulse width modulation.

15. The method of claim 11 wherein the fault condition is a short circuit.

16. The method of claim 11 wherein the load is a cap lamp.

17. A battery pack comprising:

a. a housing,

b. a battery cell positioned within said housing;

c. a pair of terminals attached to said housing for providing power from said battery cell to a load; and

d. an electronic control module positioned within said housing and in series between said pair of terminals and said battery cell, said electronic control module monitoring battery usage and, after an amount of battery usage, limiting power to the load while periodically varying the power to the load so that the load acts as indicator of a low battery charge level.

18. The battery pack of claim 17 wherein said electronic control module includes a microprocessor that monitors battery usage and limits power to the load while periodically varying the power to the load.

19. The battery pack of claim 18 wherein said electronic control module includes a coulomb counter that is in communication with the microprocessor and that the microprocessor uses to monitor battery usage.

20. The battery pack of claim 17 wherein the electronic control module limits power to the load by limiting current flow to the load and periodically provides full current to the load to vary the power to the load so that the load acts as an indicator of a low battery.

21. The battery pack of claim 20 wherein the electronic control module includes a microprocessor and a transistor, said microprocessor pulsing said transistor to limit current flow to the load.

22. The battery pack of claim 21 wherein the transistor is controlled by the microprocessor to subject the current to pulse width modulation.

23. The battery pack of claim 21 wherein the electronic control module includes a timer in communication with the microprocessor, said timer indicating to the microprocessor when to provide full current to the load.

24. The battery pack of claim 17 wherein the load is a cap lamp.

25. The battery pack of claim 17 wherein the battery cell is a Lithium-ion cell.

26. The battery pack of claim 17 wherein the electronic control module provides a charge ratio of 2:

1 when the battery pack is connected to a charger.

27. A method of providing an indication of a low battery charge level using a load receiving power from the battery comprising the steps of:

a. monitoring battery usage;

b. limiting power to the load after a predetermined amount of battery usage; and

c. periodically varying the power to the load.

28. The method of claim 27 wherein the step of limiting power to the load is accomplished by limiting current flow to the load and the step of periodically varying power to the load includes periodically providing full current to the load.

29. The method of claim 28 wherein the step of limiting current flow to the load is accomplished by pulsing a transistor.

30. The method of claim 29 wherein the transistor subjects the current to pulse width modulation.

31. The method of claim 27 wherein the load is a cap lamp.

32. A battery pack comprising:

a. a housing;

b. a battery cell positioned within said housing;

c. a pair of terminals attached to said housing for providing power from said battery cell to a load; and

d. an electronic control module positioned within said housing and in series between said pair of terminals and said battery cell, said electronic control module ramping up power to the load when the load is initially connected to the battery cell.

33. The battery pack of claim 32 wherein the electronic control module includes a microprocessor, said microprocessor ramping up power to the load when the load is initially connected to the battery cell.

34. The battery pack of claim 33 wherein the microprocessor ramps up power to the load by ramping up a flow of current from the battery cell to the load.

35. The battery pack of claim 34 wherein the electronic control module includes a transistor in communication with the microprocessor, said microprocessor pulsing said transistor to ramp up the flow of current from the battery cell to the load.

36. The battery pack of claim 35 wherein the transistor is controlled by the microprocessor to subject the current to pulse width modulation.

37. The battery pack of claim 32 wherein the load is a cap lamp.

38. The battery pack of claim 32 wherein the battery cell is a Lithium-ion battery cell.

39. A method of providing a soft start for a load receiving power from a battery cell comprising the steps of:

a. connecting the load to the battery cell; and

b. ramping up power supplied to the load from the battery cell until a predetermined power level for operating the load is reached.

40. The method of claim 39 wherein step b. includes ramping up a flow of current from the battery cell to the load.

41. The method of claim 40 wherein step b. is accomplished by pulsing a transistor.

43. The method of claim 39 wherein the load is a cap lamp.

44. The method of claim 39 wherein the battery cell is a Lithium-ion battery cell.

42. The method of step 41 wherein the transistor subjects the current to pulse width modulation.

45. A battery pack comprising:

a. a housing having an open end;

b. a separator plate positioned within said housing so that an electronic control module compartment is defined adjacent said open end and a battery compartment is defined on an opposite side of the separator plate;

c. a battery cell positioned in the battery compartment;

d. an electronic control module positioned in the electronic control module compartment, said electronic control module in communication with the battery cell;

e. a pair of battery pack terminals in communication with the electronic control module;

f. a battery post holder associated with the pair of terminals, said battery post holder sealing the otherwise open end of the battery housing; and

g. a cover removably attached to and sealing against the housing so that the pair of battery pack terminals are covered.

46. The battery pack of claim 45 wherein the electronic control module includes circuitry embedded in a potting compound.

47. The battery pack of claim 46 wherein the electronic control module includes a microprocessor embedded in a potting compound.

48. The battery pack of claim 45 wherein the battery cell is part of a battery cell bundle.

49. The battery pack of claim 48 wherein the battery cell bundle is wrapped in a vibration-reducing wrap.

50. The battery pack of claim 49 wherein the wrap is constructed from neoprene and ethylene propylene diene monomer.

51. The battery pack of claim 45 further comprising a protection circuit in series between the battery cell and the electronic control module.

52. The battery pack of claim 51 wherein the protection circuit is positioned in the battery compartment.

53. The battery pack of claim 52 wherein the protection circuit is embedded in a potting compound.

54. The battery pack of claim 45 wherein the cover includes a strain relief adapted to receive a power cord of a load.

55. The battery pack of claim 45 wherein the cover is removably attached to the housing by screws.

56. The battery pack of claim 45 further comprising an charging status LED mounted on the battery post holder and in communication with the electronic control module.

57. The battery pack of claim 56 wherein the cover includes a window that is illuminated by the charging status LED.

58. The battery pack of claim 45 wherein the battery post holder is ultrasonically welded to the housing.

59. The battery pack of claim 45 wherein the battery pack terminals extend through openings formed in the battery post holder and O-rings surround each terminal so that the terminals are sealed against the battery post holder.

60. The battery pack of claim 45 wherein the housing is constructed from polycarbonate.