BATTERY MONITORING SYSTEM

• US 20080309469A1
• Filed: 06/13/2007
• Published: 12/18/2008
• Est. Priority Date: 06/13/2007
• Status: Active Grant

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Fernandez Banares, Jose Gabriel, Ferre Fabregas, Antoni
• Granted Patent: US 8,476,864 B2
• Time in Patent Office: Days
• US Class Current: 340/438
• CPC Class Codes: G01R 1/203 Resistors used for electric measuring, e.g. decade resistors standards, resistors for comparators, series resistors, shunts resistors in general H01C; microwave or radiowave terminations H01P1/26; coupling devices H01R
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 50/569 Constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals battery terminal connectors with integrated measuring arrangements G01R31/364
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery monitor for monitoring operations of a battery, such as but not limited to monitoring operations of a vehicle battery. The battery monitor may be configured to monitor current flow and battery temperature. The battery monitor may be connected to a cable used to electrically connect the battery to a number of electronic devices so that the battery monitor is located away from the battery. The battery monitor may include a processing element grounded directly to a negative pole of the battery to facilitate isolating the processing element from noise created by the electronic devices connected to the cable.

Claims

1. A battery monitoring system for monitoring a battery used to power a number of electronic devices in a vehicle, the system comprising:

a vehicle chassis providing a vehicle ground for grounding the electronic devices powered with the battery;

a terminal adapter having one end compressively connected to a negative conducting post of the battery;

a cable attached to an other end of the terminal adapter to electrically connect the terminal adapter to the vehicle chassis, the electrical connection connecting the battery and the electronic devices to the same vehicle ground; and

a battery monitor connected between the cable and the vehicle chassis at a distance along the cable extending beyond the battery, the battery monitor including a shunt and a processing element electrically connected to the shunt, the shunt connected at one end to the cable and at an other end to the vehicle chassis for passing current from the cable to the vehicle chassis, the processing element calculating a voltage drop across the shunt for use in monitoring the battery.

2. The system of claim 1 further comprising a temperature sensor connected to the terminal adapter and having a first wire for electrically connecting the temperature sensor to the processing element, the processing element calculating a battery temperature based on signals received from the temperature sensor.

3. The system of claim 2 wherein the temperature sensor includes a negative temperature coefficient (NTC) resistor, the processing element calculating the battery temperature from a voltage drop across the NTC resistor, the voltage drop across the NTC resistor varying with battery temperature.

4. The system of claim 3 wherein the NTC resistor is grounded to the battery post.

5. The system of claim 3 wherein the NTC resistor is grounded to a printed circuit board (PCB) ground (GND electronics) of a PCB having the processing element.

6. The system of claim 5 wherein a PCB ground path is to the cable connected to the battery post.

7. The system of claim 5 further comprising as second wire for connecting the PCB directly to the battery post so that a PCB grounding path is direct to the battery post and not through the cable.

8. The system of claim 7 further comprising a third wire for electrically connecting the temperature sensor to the processing element, wherein the first and third wires connect the processing element to the NTC resistor and the second wire grounds the PCB to the battery post.

9. The system of claim 8 wherein each wire is attached to the cable to support the wires as the wires extend between the terminal adapter and the battery monitor.

10. The system of claim 3 wherein the temperature sensor includes a ring terminal for fastening the temperature sensor to the terminal adapter.

11. The system of claim 10 wherein the ring terminal and the terminal adapter are composed of a rigid metallic material to promote thermal conductivity between the battery post and temperature sensor.

12. The system of claim 3 wherein the battery monitor includes a network interface for communicating the battery temperature and the voltage drop to a vehicle system controller connected to a network bus of the vehicle.

13. The system of claim 1 wherein the battery monitor includes two connecting pins spaced apart along the shunt to electrically connect the shunt the processing element, the processing element calculating the voltage drop between the connecting pins.

14. The system of claim 1 wherein the terminal adapter is configured to extend away from and down a side of the battery for connection to the cable.

15. The system of claim 1 wherein the shunt is a planar shunt composed of a bimetallic material, the cable and vehicle chassis being fastened directly to the shunt.

16. The system of claim 1 wherein the shunt is a cylindrical shunt is composed on a bimetallic material, the cable and vehicle chassis being fastened directly to the shunt.

17. A battery monitoring system for monitoring a battery used to power a number of electronic devices in a vehicle, the system comprising:

a vehicle chassis providing a vehicle ground for grounding the electronic devices powered with the battery;

a terminal adapter having one end compressively connected to a negative conducting post of the battery;

a cable attached to an other end of the terminal adapter to electrically connect the terminal adapter to the vehicle chassis, the electrical connection connecting the battery and the electronic devices to the same vehicle ground;

a battery monitor connected between the cable and the vehicle chassis at a distance along the cable extending beyond the battery, the battery monitor including a shunt and a processing element electrically connected to the shunt, the shunt connected at one end to the cable and at an other end to the vehicle chassis for passing current from the cable to the vehicle chassis, the processing element calculating a voltage drop across the shunt for use in monitoring the battery; and

a wire grounding the processing element to the negative pole of the battery to facilitate separating the processing element from noise associated with the vehicle ground.

18. The system of claim 17 further comprising a temperature sensor fastened to a terminal adapter used to connect the cable to the battery post, the temperature sensor including a resistor configured to change resistance in proportion to a temperature of the battery, the temperature sensor being connected to the same ground as the PCB to facilitate separating the processing element from noise associated with the vehicle ground.

19. The system of claim 18 wherein the resistor is grounded directly to the battery post.

20. The system of claim 18 wherein an additional wire is included to ground the resistor to the PCB.