STATE OF CHARGE (SOC) DISPLAY FOR RECHARGEABLE BATTERY

• US 20140278170A1
• Filed: 01/31/2014
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Baruzzi, Paolo, Paparrizos, Georgios K., Garcea, Giovanni
• Application Number:
  US14/169,482
• Publication Number:
  US 20140278170A1
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables

Abstract

An initial SoC curve may be defined that relates system state of charge (SoC) as a function of battery SoC. Endpoints that define the SoC curve may be updated. For example, each time a battery SoC is determined, the SoC curve may be updated. The SoC curve may then be evaluated to produce a system SoC that can be present to the user.

Claims

1. A method for presenting state of charge (SoC) of a battery comprising:

i. storing data, including at least a first endpoint value, representative of an SoC curve that relates a system SoC as a function of a battery SoC;

ii. receiving a battery voltage measurement;

iii. receiving a battery current measurement;

iv. determining a battery SoC value using the battery voltage measurement and the battery current measurement;

v. generating an updated SoC curve by computing an updated first endpoint value of the SoC curve using a predetermined battery voltage value and a predetermined battery current value;

vi. evaluating the updated SoC curve using the battery SoC value to produce a corresponding system SoC value;

vii. displaying the system SoC value; and

repeating steps ii through vii.

2. The method of claim 1 wherein the predetermined battery voltage value is a system cutoff voltage and the predetermined battery current value is an average load current.

3. The method of claim 1 wherein the predetermined battery voltage value is a charge float voltage and the predetermined battery current value is a termination current.

4. The method of claim 1 wherein the first endpoint value is a battery SoC value that represents a 0% value of the system SoC.

5. The method of claim 1 wherein the first endpoint value is a battery SoC value that represents a 100% value of the system SoC.

6. The method of claim 1 wherein the data includes a second endpoint value of the SoC curve, wherein the SoC curve is defined by a straight line between the first and second endpoints.

7. The method of claim 6 wherein updating the SoC curve further includes computing an updated second endpoint value of the SoC curve using a second predetermined battery voltage value and a second predetermined battery current value.

8. A circuit comprising:

a memory having stored therein data representative of an SoC curve that relates a system SoC as a function of a battery SoC; and

a controller configured to;

i. receive a battery voltage measurement;

ii. receive a battery current measurement;

iii. determine a battery SoC value using the battery voltage measurement and the battery current measurement;

iv. generate an updated SoC curve by computing an updated first endpoint value of the SoC curve using a predetermined battery voltage value and a predetermined battery current value;

v. evaluate the updated SoC curve using the battery SoC value to produce a corresponding system SoC value;

vi. display the system SoC value; and

repeat steps i through vi.

9. The circuit of claim 8 wherein the predetermined battery voltage value is a system cutoff voltage and the predetermined battery current value is an average load current.

10. The circuit of claim 8 wherein the predetermined battery voltage value is a charge float voltage and the predetermined battery current value is a termination current.

11. The circuit of claim 8 wherein the first endpoint value is a battery SoC value that represents either a 0% value of the system SoC or a 100% value of the system SoC.

12. The circuit of claim 8 wherein the data includes a second endpoint value of the SoC curve, wherein the SoC curve is defined by a straight line between the first and second endpoints.

13. The circuit of claim 12 wherein updating the SoC curve further includes computing an updated second endpoint value of the SoC curve using a second predetermined battery voltage value and a second predetermined battery current value.

14. The circuit of claim 8 further comprising receiving a battery temperature measurement, wherein determining the battery SoC further uses the battery temperature measurement.

15. A circuit comprising:

first means for storing data, including at least a first endpoint value, representative of an SoC curve that relates a system SoC as a function of a battery SoC;

second means for receiving a battery voltage measurement;

third means for receiving a battery current measurement;

fourth means for determining a battery SoC value using the battery voltage measurement and the battery current measurement;

fifth means for generating an updated SoC curve by computing an updated first endpoint value of the SoC curve using a predetermined battery voltage value and a predetermined battery current value;

sixth means for evaluating the updated SoC curve using the battery SoC value to produce a corresponding system SoC value;

seventh means for displaying the system SoC value; and

means for iterating through the second means to the seventh means.

16. The circuit of claim 15 wherein the predetermined battery voltage value is a system cutoff voltage and the predetermined battery current value is an average load current.

17. The circuit of claim 15 wherein the predetermined battery voltage value is a charge float voltage and the predetermined battery current value is a termination current.

18. The circuit of claim 15 wherein the first endpoint value is a battery SoC value that represents a 0% value of the system SoC or a 100% value of the system SoC.

19. The circuit of claim 15 wherein the data includes a second endpoint value of the SoC curve, wherein the first endpoint value is a battery SoC value that represents a 0% value of the system SoC, the second endpoint value is a battery SoC value that represents a 100% value of the system SoC.

20. The circuit of claim 15 further comprising means for receiving a battery temperature measurement, wherein the fourth means for determining a battery SoC value further uses the battery temperature measurement.