Battery monitoring system

• US 8,476,864 B2
• Filed: 06/13/2007
• Issued: 07/02/2013
• Est. Priority Date: 06/13/2007
• Status: Expired due to Fees

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Ferre Fabregas, Antoni, Fernandez Baares, Jose Gabriel
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): PIGGUSH, AARON C
• Application Number:
  US11/762,424
• Publication Number:
  US 20080309469A1
• Time in Patent Office: 2,211 Days
• Field of Search: 320/104, 320/111, 320/136, 320/152, 340/438
• US Class Current: 320/104
• 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;

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 another 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 temperature sensor connected to the terminal adapter and having a wire for electrically connecting the temperature sensor to the processing element, the wire being independent of the cable and extending a distance D away from the battery, the battery monitor being positioned at a distance along the cable such that the cable is approximately as long as the distance D, the processing element calculating a battery temperature based on signals received from the temperature sensor.

2. The system of claim 1 wherein the temperature sensor includes a resistor, the processing element calculating the battery temperature from a voltage drop across the resistor, the voltage drop across the resistor varying with battery temperature and wherein the resistor is grounded to the battery post with a ring terminal affixed to the terminal adapter.

3. The system of claim 1 wherein the temperature sensor includes a resistor, the processing element calculating the battery temperature from a voltage drop across the resistor, the voltage drop across the resistor varying with battery temperature wherein the resistor is grounded to a printed circuit board (PCB) ground (GND electronics) of a PCB having the processing element.

4. The system of claim 3 wherein a PCB ground path is to the cable connected to the battery post, thereby causing the PCB ground to have a greater ground voltage than the PCB ground would have if connect directly to the negative conducting post of the battery.

5. The system of claim 3 further comprising a second wire for connecting the PCB directly to the negative conducting post of the battery so that a PCB grounding path is direct to the battery post and not through the cable.

6. The system of claim 5 further comprising a third wire for electrically grounding the temperature sensor to the processing element, wherein the first and third wires connect the processing element to the resistor and the second wire grounds the PCB to the battery post.

7. The system of claim 6 wherein each wire is attached to the cable to support the wires as the wires extend between the terminal adapter and the battery monitor.

8. The system of claim 1 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 and a temperature sensor interface for communicating with the temperature sensor.

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

10. The system of claim 1 wherein the terminal adapter is L-shaped and configured to have one leg of the L-shape extending down a lateral, exterior side of the battery leading downwardly from a top of the battery coplanar with the negative conducting post, the one leg extending down the side where at the one leg is connected to the cable.

11. The system of claim 1 wherein the shunt is one of a planar shunt composed of a bi-metallic material, the cable and vehicle chassis being fastened directly to the shunt, and a cylindrical shunt is composed on a bi-metallic material, the cable and vehicle chassis being fastened directly to the shunt, wherein the cable is longer than an entire exterior width of the battery.

12. The system of claim 1 wherein the temperature sensor is external to the battery monitor and directly connected to the negative conducting post of the battery, the distance D being at least twice as long as an entire length of the battery monitor.

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

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

a flexible cable attached to an other end of the terminal adapter and extending a first distance away from the battery, the first distance being sufficient for the cable to extend beyond a perimeter of the battery;

a battery monitor including a processing element electrically connected to a shunt, the shunt connected at one end to the cable and at another end to a vehicle chassis for passing current from the cable to the vehicle chassis, the vehicle chassis defining a vehicle ground, the processing element calculating a voltage drop across the shunt for use in monitoring the battery;

a wire extending from the processing element to the negative pole of the battery, the wire establishing a processing element ground sufficient to facilitate separating the processing element from noise associated with the vehicle ground, the wire being at least approximately as long as the first distance; and

a temperature sensor connected to the terminal adapter and electrically connected to the processing element, the battery monitor being positioned at a distance D along the flexible cable away from the battery such that the flexible cable is approximately as long as the distance D, the processing element calculating a battery temperature based on signals received from the temperature sensor.

14. The system of claim 13, wherein the temperature sensor comprises a resistor configured to change resistance in proportion to a temperature of the battery, the temperature sensor being connected to the processing element ground to facilitate separating the processing element from noise associated with the vehicle ground.

15. The system of claim 14 wherein the resistor is grounded directly to the battery post.

16. The system of claim 14 wherein an additional wire is included to ground the resistor to the processing element ground, the additional wire being at least as long as the first distance, the first distance being longer than an entire length of the battery monitor.

17. The system of claim 13 wherein the first distance is greater than an entire exterior width of the battery and the temperature sensor is external to the battery monitor and connected directly to the negative conducting post of the battery.

18. A battery monitoring system comprising:

a non-flexible shunt having a first end and a second end, the first end operably connected to a flexible cable leading a first length away to a battery post and the second end operably connected to a vehicle chassis;

a processing element operable to calculate a voltage drop across the shunt for use in outputting signaling used in battery monitoring;

wherein the processing element is grounded to the battery post, and not the vehicle chassis, with a wire approximately equal in length to the first length, a majority of the wire running exterior to the flexible cable and to a housing enclosing the processing element and the shunt; and

a temperature sensor electrically connected to the processing element, the processing element being positioned at a distance D along the flexible cable away from the battery post such that the flexible cable is approximately as long as the distance D, the processing element calculating a battery temperature based on signals received from the temperature sensor.

19. The battery monitoring system of claim 18 wherein the wire is smaller in diameter than the flexible cable.