Motor vehicle battery disconnect circuit having electronic disconnects
View Patent ↗An electronic disconnect switch module ( 12 ) in a motor vehicle has one or more pairs of high-current, high-side solid state switch devices ( 30 A, 30 B, 32 A, and 32 B). 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.
1. A disconnect switch module for disconnecting a battery bank from an electrical load upon occurrence of certain conditions, the module comprising 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 further comprising 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 electrical load when data corresponding to battery bank voltage indicates that a battery has been connected in the battery bank to create a double battery.
2. The combination of a battery bank comprising one or more D.C. storage batteries, an electrical load circuit, and a disconnect switch module for disconnecting the battery bank from the electrical load circuit upon occurrence of certain conditions, the disconnect switch module comprising 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 electrical load circuit, 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 further comprising 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 electrical load circuit when data corresponding to battery bank voltage indicates that a battery has been connected in the battery bank to create a double battery.
3. The combination set forth in claim 2 further comprising 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 processed data, control data for controlling the solid-state switches.
4. The combination set forth in claim 3 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.
5. The combination set forth in claim 4 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.
6. The combination set forth in claim 3 wherein the processor comprises an algorithm that when executed, develops data that causes either a) limiting battery bank charge current 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.
7. The combination set forth in claim 3 further comprising an indicator operable by the module for disclosing that the module has disconnected the electrical load from the battery bank, a person-operated reset switch, and wherein the module comprises a reset input to which the reset switch is connected for resetting the module from a disconnected state to a connected state in response to operation of the reset switch.
8. The combination set forth in claim 3 further comprising a person-operated switch, and wherein the module comprises an input to which the person-operated switch is connected for switching the module from a connected state to a disconnected state in response to operation of the person-operated switch.
9. The combination as set forth in claim 2 further comprising 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 electrical load when data corresponding to battery bank voltage indicates battery bank voltage has dropped below a low voltage threshold.
10. The combination as set forth in claim 2 further comprising 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 electrical load circuit when data corresponding to battery bank voltage indicates a reversed polarity battery in the battery bank.