Intelligent switch for battery

• US 6,320,351 B1
• Filed: 01/24/2001
• Issued: 11/20/2001
• Est. Priority Date: 05/08/2000
• Status: Expired due to Fees

• Current Assignee: Sunlite Trading Limited
• Original Assignee: Sunlite Trading Limited
• Inventors: Ng, Wai Man, Choi, Kong Fan
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/769,226
• Publication Number:
  US 20010040441A1
• Time in Patent Office: 300 Days
• Field of Search: 320/103, 320/104, 320/134, 320/136
• US Class Current: 320/104
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles
• CPC Class Codes: H02J 7/0032 disconnection of loads if battery is not under charge, e.g. in vehicle if engine is not running

Abstract

An intelligent switch for preventing over discharge of a vehicle battery includes a switch connected to toggle between a first state for preventing current flow from the battery and a second state for allowing current flow from the battery. A voltage monitor provides a voltage signal indicative of the voltage level of the battery. A vibration sensor provides a vibration signal indicative of vehicle vibration. A controller is connected to receive the voltage signal and the vibration signal and generate a control signal for toggling the switch to the first state when no vibration of the vehicle is detected and the voltage level of the battery falls below a predetermined voltage threshold. The controller generates another control signal when vibration is detected to toggle the switch to the second state. Multiple voltage thresholds and associated timers are used to maintain an adequate battery charge level under variable load conditions.

Claims

1. An intelligent switch for preventing undesirable discharge of a battery of a vehicle, comprising:

a switch connected in circuit with the battery and being configured to toggle between a first state for preventing current flow from the battery and a second state for allowing current flow from the battery;

a voltage monitor connected to the battery and being configured to provide a voltage signal indicative of the voltage level of the battery;

a vibration sensor configured to detect vibration of the vehicle and provide a vibration signal indicative thereof; and

a controller connected to receive the voltage signal and the vibration signal and being configured to generate a control signal for toggling the switch to the first state when no vibration of the vehicle is detected and the voltage level of the battery falls below a predetermined voltage threshold and to the second state when vibration is detected regardless of the voltage level of the battery.

2. The intelligent switch of claim 1, wherein the voltage monitor is configured to output the voltage signal when the voltage from the battery falls below the predetermined voltage threshold, the voltage signal being detected by the controller.

3. The intelligent switch of claim 1, wherein the controller comprises a central processing unit.

4. The intelligent switch of claim 1, wherein the controller comprises a microprocessor.

5. The intelligent switch of claim 1, further comprising a timer circuit for providing a predetermined delay between when the voltage level falls below the predetermined threshold value and the output of the control signal from the controller so that should vibrations be detected the control signal will not be output from the controller.

6. The intelligent switch of claim 5, wherein the predetermined delay is about thirty seconds.

7. The intelligent switch of claim 1, wherein the switch comprises a latching relay.

8. The intelligent switch of claim 7, wherein the control signal comprises a control pulse.

9. The intelligent switch of claim 1, wherein the vibration sensor outputs a vibration signal upon vibration of the vehicle.

10. The intelligent switch of claim 9, wherein vibration sensor comprises a piezoelectric disc or a magnetic sensor.

11. The intelligent switch of claim 7 further comprising a power management unit for supplying power to the voltage monitor, vibration sensor, controller and latching relay.

12. The intelligent switch of claim 1, wherein the predetermined voltage threshold is approximately 12.1 volts.

13. The intelligent switch of claim 1 wherein the battery comprises a positive terminal and the intelligent switch is incorporated within the battery in circuit with the positive terminal.

14. An intelligent switch for preventing undesirable discharge of a battery for a vehicle, comprising:

a switch connected in circuit with the battery and being configured to toggle between a first state for preventing current flow from the battery and a second state for allowing current flow from the battery;

a voltage monitor connected to the battery and being configured to provide a low voltage signal when the voltage from the battery falls below a predetermined voltage threshold level;

a vibration sensor configured to detect vibration of the vehicle and provide a vibration signal indicative thereof; and

a controller connected to receive the low voltage signal and the vibration signal and being configured to generate a control signal for toggling the switch to the first state when no vibration of the vehicle is detected and to the second state when vibration is detected.

15. A method of preventing undesirable discharge of a battery for a vehicle, comprising the steps of:

monitoring a voltage level of the battery and providing a voltage signal indicative of the voltage level;

detecting vibration of the vehicle and providing a vibration signal indicative thereof;

receiving the voltage signal and the vibration signal;

generating a control signal based on the voltage signal when the voltage level from the battery falls below a predetermined threshold voltage level and based on the vibration signal when no vibration of the vehicle is detected, the control signal toggling a switch to a first state for preventing current flow from the battery; and

generating another control signal for toggling the switch to a second state for allowing current flow from the battery when vibration is again detected.

16. The method of claim 15 further comprising the step of delaying the generation of the control signal after the voltage level falls below the predetermined voltage threshold value.

17. The method of claim 16, wherein the delay is about thirty seconds.

18. The method of claim 15, wherein the switch comprises a latching relay.

19. The method of claim 18, wherein the control signal comprises a control pulse.

20. The method of claim 15, wherein the predetermined voltage threshold value is about 12.1 volts.

21. An intelligent switch for preventing undesirable discharge of a rechargeable vehicle battery, comprising:

a switch connected in circuit with the battery and being configured to toggle between a first state for preventing current flow from the battery and a second state for allowing current flow from the battery;

a voltage monitor connected to the battery and being configured to provide a voltage signal indicative of the voltage level of the battery;

a vibration sensor configured to detect vibration of the vehicle and provide a vibration signal indicative thereof;

a controller connected to receive the voltage signal and the vibration signal and being configured to generate a control signal for toggling the switch to the first state when no vibration of the vehicle is detected subsequent to the voltage level of the battery falling below a predetermined voltage threshold and to the second state when vibration is detected; and

at least one timer configured to start counting a predetermined period of time in response to the voltage level of the battery falling below the predetermined voltage threshold, at the end of which predetermined period of time the controller is to generate said control signal for toggling the switch to the first state.

22. The intelligent switch of claim 21, wherein the controller comprises a microprocessor.

23. The intelligent switch of claim 21, wherein the battery comprises a positive terminal and the intelligent switch is incorporated within the battery in circuit with the positive terminal.

24. The intelligent switch of claim 21, wherein the switch comprises a latching relay.

25. The intelligent switch of claim 21, wherein the vibration sensor comprises a piezoelectric disc or a magnetic sensor.

26. The intelligent switch of claim 24, further comprising a power management unit for supplying power to the voltage monitor, vibration sensor, controller, at least one timer and latching relay.

27. The intelligent switch of claim 21, wherein the battery is a battery for starting an engine of the vehicle.

28. The intelligent switch of claim 21, wherein the battery comprises a first part primarily for starting the engine of the vehicle and a second part primarily for supplying power to an electrical load of the vehicle, to which first and second battery parts the voltage monitor is connected, and the intelligent switch includes first and second said switches connected in circuit with the first and second battery parts respectively.

29. The intelligent switch of claim 28, wherein the controller is configured to generate a first control signal for toggling the first switch to the first state when no vibration of the vehicle is detected subsequent to the voltage level of the first battery part falling below a first predetermined voltage threshold and subsequently to generate a second control signal for toggling the second switch to the first state when no vibration of the vehicle is detected and the voltage level of the second battery part falls below a second predetermined voltage threshold, said second predetermined voltage threshold being lower than said first predetermined voltage threshold.

30. The intelligent switch of claim 29, wherein the first and second predetermined voltage thresholds are about 12.8 volts and 10.8 volts, respectively.

31. The intelligent switch of claim 21, wherein the controller is configured with at least two said predetermined voltage thresholds, and the intelligent switch includes one said timer associated with each said predetermined voltage threshold, a first of said timers being for counting a relatively longer predetermined period of time corresponding to the predetermined voltage threshold that is relatively higher, and a second of said timers being for counting a relatively shorter predetermined period of time corresponding to the predetermined voltage threshold that is relatively lower.

32. The intelligent switch of claim 31, wherein the controller is configured to generate said control signal when any one of the predetermined periods of time is counted to an end.

33. The intelligent switch of claim 21, wherein the controller is configured with five said predetermined voltage thresholds, and the intelligent switch includes one said timer associated with each predetermined voltage threshold for counting predetermined periods of time associated with each predetermined voltage threshold, the predetermined period of time associated with a higher voltage threshold being longer than the predetermined period of time associated with a relatively lower voltage threshold.

34. The intelligent switch of claim 33, wherein each timer is configured to stop counting when the voltage level of the battery rises back above the predetermined voltage threshold associated with the timer and to resume counting if the voltage level of the battery falls below the predetermined voltage threshold associated with the timer, said timer resuming said counting where said counting stopped and counting for a period of time corresponding to a remainder of said predetermined period of time associated with said timer.

35. The intelligent switch of claim 21, wherein each said at least one timer comprises a count down timer.

36. The intelligent switch of claim 34, wherein the controller is configured to generate said control signal when any one of the predetermined periods of time is counted to an end.

37. A method of preventing undesirable discharge of a battery for a vehicle, comprising the steps of:

monitoring a voltage level of the battery and providing a voltage signal indicative of the voltage level;

detecting vibration of the vehicle and providing a vibration signal indicative thereof;

receiving the voltage signal and the vibration signal;

generating a control signal based on the voltage signal when the voltage level from the battery falls below a predetermined threshold voltage level in the absence of vehicle vibration, the control signal toggling a switch to a first state for preventing current flow from the battery; and

generating another control signal for toggling the switch to a second state for allowing current flow from the battery when vibration is again detected.

38. The method of claim 37, further comprising the step of delaying the generation of the control signal after the voltage level falls below the predetermined voltage threshold value.

39. The method of claim 38, wherein said step of delaying comprises the steps of starting to count a first predetermined period of time when the voltage level from the battery falls below a first predetermined threshold voltage level, and the step of starting to count a second, relatively shorter predetermined period of time when the voltage level from the battery falls below a second, relatively lower predetermined threshold voltage level, prior to the generation of the control signal.

40. The method of claim 39, wherein the control signal is generated when any one of the predetermined periods is counted to an end.