Motor vehicle battery disconnect circuit having electronic disconnects

• US 7,612,524 B2
• Filed: 09/29/2006
• Issued: 11/03/2009
• Est. Priority Date: 09/29/2006
• Status: Expired due to Fees

• Current Assignee: International Truck Intellectual Property Co. LLC (Volkswagen AG)
• Original Assignee: International Truck Intellectual Property Co. LLC (Volkswagen AG)
• Inventors: Kelwaski, H. Edward, Howell, Clayton M., Jervis, John D.
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): PIGGUSH, AARON C
• Application Number:
  US11/536,959
• Publication Number:
  US 20080079389A1
• Time in Patent Office: 1,131 Days
• Field of Search: 320/104, 320/162, 320/163, 320/158, 320/132, 320/134, 324/427
• US Class Current: 320/104
• 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 7/1438 in combination with power supplies for loads other than batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

An electronic disconnect switch module (12) in a motor vehicle has one or more pairs of high-current, high-side solid state switch devices (30A, 30B, 32A, and 32B). The source terminal of one device of each pair is connected to vehicle load circuits (27), the source terminal of the other device of each pair is connected to the vehicle battery bank (16), and the drain terminals of the devices of each pair are connected in common. The module also has a microcontroller (34) that interfaces the switch devices with the vehicle electrical system. Four feature groups are provided: Vehicle Electrical System Protection, Battery Charge Control, Battery Disconnect, and Battery Monitoring.

Claims

1. An engine-powered land vehicle comprising:

an engine and a drivetrain through which the engine propels the vehicle on land;

a battery bank comprising one or more D.C. storage batteries;

an electric starter motor that draws current from the battery bank to crank the engine at starting;

electric load circuits that are fed from the battery bank through a disconnect switch module,

wherein the disconnect switch module comprises one or more pairs of high-current, high-side solid state switch devices, the devices of each pair each comprising a solid-state switch comprising a source terminal and a drain terminal providing a conduction path through the switch, the source terminal of one device of each pair being connected to the load circuits, the source terminal of the other device of each pair being connected to the battery bank, and the drain terminals of the devices of each pair being connected in common, and

wherein the module comprises a processor that is associated with each solid-state switch and that comprises an algorithm for processing data corresponding to battery bank voltage for causing the solid-state switches to disconnect the battery bank from the electric load circuits when data corresponding to battery bank voltage indicates that a battery has been connected in the battery bank to create a double battery.

2. A vehicle as set forth in claim 1 wherein the module comprises a processor that is associated with each solid-state switch and that comprises an algorithm for processing data relevant to operation of the disconnect switch module and for developing from that processed data control data for controlling the solid-state switches.

3. A vehicle as set forth in claim 2 wherein the data relevant to operation of the disconnect switch module includes data representing a) the magnitude and direction of electric current flow through the disconnect switch module with respect to the battery bank, and b) the open circuit voltage of the battery bank.

4. A vehicle as set forth in claim 3 wherein the control data for controlling the disconnect switch module is developed by also processing programmed data defining the number of batteries in the battery bank and the ampere-hour rating of each battery in the battery bank.

5. A vehicle as set forth in claim 2 further including an alternator for charging the battery bank, and wherein the processor comprises an algorithm that when executed, develops data that causes either a) limiting battery bank charge current from the alternator to a defined charge current limit without regulating battery bank voltage, b) regulating battery bank voltage to a first defined limit of regulation when charge current is within a defined range immediately below the defined charge current limit, or c) regulating battery bank voltage to a second defined limit of regulation that is less than the first defined limit of regulation when charge current is less than the defined range.

6. A vehicle as set forth in claim 2 further comprising a data link via which the processor has communication with an electrical system of the vehicle that contains a reset switch for resetting the module from a disconnected state to a connected state when an indicator indicates that the module is in the disconnected state.

7. A vehicle as set forth in claim 2 further comprising a data link via which the processor has communication with an electrical system of the vehicle that contains a switch for switching the module from a connected state to a disconnected state.

8. A vehicle as set forth in claim 1 wherein the module comprises a processor that is associated with each solid-state switch and that comprises an algorithm for processing data corresponding to battery bank voltage for causing the solid-state switches to disconnect the battery bank from the electric load circuits when data corresponding to battery bank voltage indicates battery bank voltage has dropped below a low voltage threshold.

9. A vehicle as set forth in claim 1 wherein the module comprises a processor that is associated with each solid-state switch and that comprises an algorithm for processing data corresponding to battery bank voltage for causing the solid-state switches to disconnect the battery bank from the electric load circuits when data corresponding to battery bank voltage indicates a reversed polarity battery in the battery bank.

10. A method for protecting a battery bank having one or more D.C. storage batteries in an electrical system of an engine-powered land vehicle against loss of charge that renders the battery bank incapable of operating an electric starter motor that draws current from the battery bank to crank the engine at starting, the electrical system having electric load circuits that are fed from the battery bank through a disconnect switch module that comprises controlled conduction solid-state switch devices through which current can bi-directionally flow between the battery bank and the electric load circuits, the method comprising:

processing data relevant to operation of the solid-state switch devices and developing from that processed data control data for controlling the solid-state switches to either a) limit charge current to the battery bank to a defined charge current limit without regulating battery bank voltage, b) regulate battery bank voltage to a first defined limit of regulation when charge current is within a defined range immediately below the defined charge current limit, or c) regulate battery bank voltage to a second defined limit of regulation that is less than the first defined limit of regulation when charge current is less than the defined range; and

processing data corresponding to battery bank voltage and causing the solid-state switches to disconnect battery bank from the electric load circuits when data corresponding to battery bank voltage indicates that a battery has been connected in the battery bank to create a double battery.

11. A method as set forth in claim 10 including processing data representing a) the magnitude and direction of electric current flow through the disconnect switch module with respect to the battery bank, and b) the open circuit voltage of the battery bank.

12. A method as set forth in claim 11 including processing programmed data defining the number of batteries in the battery bank and the ampere-hour rating of each battery in the battery bank.

13. A method as set forth in claim 10 including processing data corresponding to battery bank voltage and causing the solid-state switches to disconnect the battery bank from the electric load circuits when data corresponding to battery bank voltage indicates battery bank voltage has dropped below a low voltage threshold.

14. A method as set forth in claim 10 including processing data corresponding to battery bank voltage and causing the solid-state switches to disconnect the battery bank from the electric load circuits when data corresponding to battery bank voltage indicates a reversed polarity battery in the battery bank.