Battery system

• US 6,452,361 B2
• Filed: 07/23/2001
• Issued: 09/17/2002
• Est. Priority Date: 02/13/1998
• Status: Expired due to Term

• Current Assignee: CPS Technology Holdings, LLC
• Original Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Iverson, Michael E., Segall, William P., Dougherty, Thomas J.
• Primary Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/912,675
• Publication Number:
  US 20020008495A1
• Time in Patent Office: 421 Days
• Field of Search: 320/104, 320/103, 320/132, 320/162, 429/9, 429/90, 307/43, 307/66
• US Class Current: 320/104
• CPC Class Codes: G08B 29/181 due to failing power supply
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery system for use in a vehicle is disclosed having a first battery for selectively powering the motor to start the engine, and having a first voltage level and a charge level. The system includes a second battery to operate and maintain the accessory electrical loads, and having a second voltage level. The system includes a charging switch coupling the first battery to the alternator. The system also includes a charge maintenance device coupling the first battery to the second battery to maintain the charge level of the first battery to a predefined magnitude in response to a control signal. The system also includes a controller coupled to both the first battery and the second battery to monitor the first voltage level and the second voltage level, and operating the charging switch and the charge maintenance device in response to the first voltage level and the second voltage level.

Claims

1. A battery system for use in a vehicle having an electric motor for starting an engine, an alternator driven by the engine to generate electricity, and accessory electrical loads comprising:

a first battery for selectively powering the motor to start the engine, and having a first voltage level and a charge level;

a second battery to operate and maintain the accessory electrical loads, and having a second voltage level;

a charging switch connecting the first battery to the alternator;

a charge maintenance device connecting the first battery to the second battery

to maintain the charge level of the first battery to a predefined magnitude in response to a control signal;

a controller coupled to both the first battery and the second battery to monitor the first voltage level and the second voltage level, and operating the charging switch and the charge maintenance device in response to the first voltage level and the second voltage level.

2. The battery system of claim 1 wherein the controller produces the control signal thereby activating the charge maintenance device when the first battery requires charging while the alternator is not substantially generating electricity.

3. The battery system of claim 1 wherein the controller closes the charging switch in response to the second charge level being greater than a first threshold, and opens the charging switch in response to the second charge level being less than a second threshold.

4. The battery system of claim 3 wherein the second threshold is less than the first threshold.

5. The battery system of claim 1 further comprising a power switch which connects the accessory electrical loads to the first battery and which is connected to the controller, wherein the controller operates the power switch in response to the second charge level.

6. The battery system of claim 1 further comprising a power switch which connects the accessory electrical loads to the first battery and which is connected to the controller, wherein the controller operates the power switch to disconnect accessory electrical loads when the second charge level is below a given threshold.

7. The battery system of claim 1 wherein the charge maintenance device responds to the control signal by applying a series of current pulses to recharge the first battery.

8. The battery system of claim 1 wherein the charge maintenance device comprises a charge pump.

9. The battery system of claim 1 further comprising a receiver for sending a signal to the controller to disengage the power switch.

10. A battery system for use in a vehicle having an electric motor for starting an engine, an alternator driven by the engine to generate electricity, and accessory electrical loads comprising:

a first battery for selectively powering the electric motor to start the engine, and having a first charge level;

a second battery to operate and maintain the accessory electrical loads, and having a second charge level;

means for maintaining a charge of the first battery at a predefined level;

means for operating the means for maintaining a charge of the first battery at the predefined level in response to the first charge level.

11. The battery system of claim 10 wherein the means for maintaining a charge of the first battery at the predefined level connects the first battery to the second battery.

12. The battery system of claim 11 wherein the means for maintaining the charge of the first battery at the predefined level comprises a charge maintenance device.

13. The battery system of claim 12 wherein the means for maintaining a charge comprises a controller coupled to the first battery.

14. The battery system of claim 13 wherein the controller is configured to enable the charge maintenance device in response to the first charge level being less than a first threshold, and is configured to disable the charge maintenance device in response to the first charge level being greater than a second threshold greater than the first threshold.

15. A battery system for use in a vehicle having a motor for starting an engine, an alternator driven by the engine to generate electricity, and accessory electrical loads comprising:

a first battery for selectively powering the motor to start the engine, and having a first charge level;

a second battery to operate and maintain the accessory electrical loads, and having a second charge level;

a charge maintenance system configured to maintain a charge of the first battery at a predefined level; and

a controller coupled to the first battery to monitor the first charge level, and operating the charge maintenance system in response to the first charge level.

16. The battery system of claim 15 wherein the charge maintenance system couples the first battery to the second battery.

17. The battery system of claim 15 wherein the second battery includes a glass mat.

18. The battery system of claim 16 wherein the second battery has a relatively high reserve capacity and is adapted to provide a relatively low-rate discharge for an extended period.

19. The battery system of claim 16 wherein the controller is configured to activate the charge maintenance system when the first battery requires charging while the alternator is not substantially generating electricity.

20. The battery system of claim 16 further comprising a charging switch coupling the first battery to the alternator and being coupled to the controller.

21. The battery system of claim 20 wherein the controller is configured to operate the charging switch in response to voltage across the second battery.

22. The battery system of claim 21 wherein the controller is configured to close the charging switch in response to the voltage across the second battery being greater than a first threshold, and configured to open the charging switch in response to the voltage across the second battery being less than a second threshold.

23. The battery system of claim 22 wherein the second threshold is less than the first threshold.

24. The battery system of claim 16 further comprising a power switch which couples the accessory electrical loads to one of the first battery and the second battery, and which is coupled to the controller.

25. The battery system of claim 24 wherein the controller is configured to operate the power switch in response to voltage across the second battery.

26. The battery system of claim 25 further comprising a power switch which couples the accessory electrical loads to the first battery, and which is coupled to the controller.

27. The battery system of claim 26 wherein the controller is configured to operate the power switch to disconnect the accessory electrical loads when voltage across the second battery is below a given threshold.

28. The battery system of claim 16 wherein the charge maintenance system is configured to respond to a control signal from the controller by applying a series of current pulses to recharge the first battery.

29. The battery system of claim 16 wherein the charge maintenance system comprises a charge pump.

30. The battery system of claim 16 further comprising a charging switch in a first circuit path between the first battery and the second battery and the alternator, the charging switch coupling the first battery to the second battery and the alternator.

31. The battery system of claim 16 wherein the controller is coupled to the second battery to monitor the second charge level.

32. The battery system of claim 31 wherein the controller is configured to enable and disable the charge pump in response to the first charge level.

33. The battery system of claim 32 wherein the controller is configured to open and close the charging switch in response to the second charge level.

34. The battery system of claim 16 wherein the controller is configured to enable the charge pump in response to the first charge level being less than a first threshold, and configured to disable the charge pump in response to the first charge level being greater than a second threshold greater than the first threshold.

36. The charge management system of claim 34 wherein the charge maintenance system couples the first battery to the second battery until the first charge of the first battery reaches a predetermined value.

37. The charge management system of claim 36 wherein the predetermined value of the first charge of the first battery is greater than about 13V.

38. The charge management system of claim 36 wherein the charge maintenance system couples the first battery to the second battery for a predetermined time.

39. The charge management system of claim 38 wherein the predetermined time for coupling the first battery to the second battery is less than about 24 hours.

40. The charge management system of claim 36 wherein the charge maintenance system disconnects the second battery from the accessory when the second charge of the second battery is less than about 12.2V.

41. The charge management system of claim 36 wherein the charge maintenance system comprises a transistor for disconnecting the accessory from the second battery.

42. The charge management system of claim 41 wherein the charge maintenance system comprises a MOSFET for disconnecting the accessory from the second battery.

43. The charge management system of claim 36 wherein the charge maintenance system disconnects the accessory from the first battery when first charge is less than a predetermined value.

44. The charge management system of claim 36 wherein the first battery is a starting battery and the second battery is a reserve battery.

45. The charge management system of claim 44 wherein the second battery is an absorptive glass mat battery.

46. The charge management system of claim 44 wherein at least one of the first battery and the second battery is a capacitor.

47. The charge management system of claim 44 wherein the charge maintenance system comprises a control system.

48. The charge management system of claim 47 wherein the charge maintenance system further comprises a controller.

49. The charge management system of claim 48 wherein the charge maintenance system further comprises a computer for executing a control program.

50. The charge management system of claim 48 wherein the charge maintenance system is under the control of the control program.

51. The charge management system of claim 50 wherein the charge maintenance system comprises a charge pump.

52. The charge management system of claim 50 wherein the charge maintenance system comprises a charge maintenance device.

53. The charge management system of claim 50 wherein the accessory comprises an interior light.

54. The charge management system of claim 53 further comprising an input device for selectively disconnecting and reconnecting the first battery with the ignition system.

35. A charge management system for a vehicle comprising:

a first battery having a first charge for powering a vehicle ignition system;

a second battery having a second charge for powering at least one electrical accessory;

a charge maintenance system coupled to the first battery and the second battery and configured to;

(a) monitor at least one of the first charge of the first battery and the second charge of the second battery;

(b) maintain the first charge of the first battery at a predetermined value by selectively coupling the first battery to the second battery; and

(c) disconnect the second battery from the accessory when the second charge of the second battery is at a predetermined value.