Method and system for determining a state of charge of a battery

• US 8,212,519 B2
• Filed: 03/15/2011
• Issued: 07/03/2012
• Est. Priority Date: 11/29/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Koch, Brian J., Conell, Robert S., Verbrugge, Mark W., Meisner, Gregory P.
• Primary Examiner(s): Koval, Melissa
• Assistant Examiner(s): BOATENG, ALEXIS ASIEDUA
• Application Number:
  US13/048,716
• Publication Number:
  US 20110166811A1
• Time in Patent Office: 476 Days
• Field of Search: 320/134, 320/132, 320/107, 320/135, 320/136, 320/108, 320/124, 320/137, 320/149, 320/104, 324/426, 324/427, 324/428
• US Class Current: 320/108
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: H01F 7/0273 Magnetic circuits with PM for magnetic field generation
• CPC Class Codes: H01F 7/0278 for generating uniform fields, focusing, deflecting electrically charged particles for magnetic separation by Lorentz force B03C1/023; specially adapted for NMR applications G01R33/383
• CPC Class Codes: H02J 7/32 for charging batteries from a charging set comprising a non-electric prime mover rotating at constant speed

Abstract

Methods and systems are provided for determining a state of charge of a battery. The battery is subjected to a predetermined magnetic field such that the battery and the predetermined magnetic field jointly create a resultant magnetic field. The resultant magnetic field is sensed. The state of charge of the battery is determined based on the resultant magnetic field.

Claims

1. An apparatus comprising:

a battery;

a magnetic sensor is one of located adjacent to and attached to the battery; and

a state of charge module in operable communication with the magnetic sensor, the state of charge module being configured to;

subject the battery to a predetermined magnetic field such that the battery and the state of charge module jointly create a resultant magnetic field; and

to detect an electromagnetic response to the predetermined magnetic field.

2. The apparatus of claim 1, wherein the predetermined magnetic field is applied by a permanent magnet.

3. The apparatus of claim 1, wherein the state of charge module comprises:

an output amplifier;

a first conductive winding configured to induce the predetermined magnetic field in the battery by conducting a first current flow;

a second conductive winding configured to conduct a second current flow induced in the second conductive winding by the resultant magnetic field; and

a control circuit configured to adjust the first current flow and the second current flow to produce a balanced input to the output amplifier.

4. The apparatus of claim 3, wherein the first conductive winding and the second conductive winding are wound around the battery.

5. The apparatus of claim 3, wherein the first conductive winding at least partially overlaps the second conductive winding.

6. The apparatus of claim 3, wherein the control circuit comprises a variable inductor connected in series with the first conductive winding and the second conductive winding.

7. The apparatus of claim 6, wherein the control circuit comprises a variable resistor connected in parallel with the second conductive winding and the variable inductor.

8. The apparatus of claim 7, wherein the output amplifier receives an input from the variable resistors.