Method and Circuitry to Calculate the State of Charge of a Battery/Cell

• US 20120203483A1
• Filed: 10/12/2011
• Published: 08/09/2012
• Est. Priority Date: 06/24/2010
• Status: Active Grant

• Current Assignee: Qnovo, Inc.
• Original Assignee: NEIL Steinberg
• Inventors: Ghantous, Dania, Berkowitz, Fred, Maluf, Nadim
• Granted Patent: US 8,427,112 B2
• 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 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/388 involving voltage measurements
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• 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: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The present inventions, in one aspect, are directed to techniques and/or circuitry to determine the state of charge of a battery/cell using data which is representative of an overpotential of the battery/cell. In yet another aspect the present inventions are directed to techniques and/or circuitry to adaptively charge a battery/cell using data which is representative of a state of charge of the battery/cell and/or the data which is representative of an overpotential of the battery/cell.

Claims

1. A method to determine a state of charge of a battery, wherein the battery includes at least two terminals, the method comprising:

applying a signal to the terminals of the battery, wherein the signal includes at least one pulse;

measuring a terminal voltage of the battery which is a voltage between the terminals of the battery, wherein measuring the terminal voltage of the battery includes measuring a first terminal voltage of the battery which is in response to a first pulse of the signal and at a first predetermined time relative to applying the first pulse of the signal to the terminals of the battery;

monitoring the terminal voltage of the battery after applying the first pulse of the signal to the terminals of the battery and before applying a second pulse of the signal to the terminals of the battery to determine a second terminal voltage, wherein the second terminal voltage of the battery is a voltage which correlates to an equilibrium voltage of the battery;

calculating data which is representative of an overpotential of the battery using the first terminal voltage of the battery and the second terminal voltage of the battery;

determining data which is representative of a state of charge of the battery using the data which is representative of the overpotential of the battery; and

outputting the data which is representative of the state of charge of the battery.

2. The method of claim 1 wherein outputting the data which is representative of the state of charge of the battery includes displaying the data which is representative of the state of charge of the battery.

3. The method of claim 1 wherein the voltage which correlates to the equilibrium voltage of the battery is a terminal voltage of the battery which is substantially constant after application of the first pulse of the signal to the terminals of the battery and before applying the second pulse of the signal to the terminals of the battery.

4. The method of claim 1 wherein the first pulse is a charge pulse or a discharge pulse.

5. The method of claim 1 further including determining the equilibrium voltage of the battery using (i) the second terminal voltage and (ii) characteristics of a decay of the terminal voltage associated with the battery and wherein calculating data which is representative of the overpotential of the battery uses the first terminal voltage of the battery and the equilibrium voltage of the battery.

6. The method of claim 1 wherein measuring a first terminal voltage of the battery at a first predetermined time relative to applying the signal to the terminals of the battery includes measuring the first terminal voltage immediately before or at a beginning of the first pulse of the signal.

7. The method of claim 1 wherein measuring a first terminal voltage of the battery at a first predetermined time relative to applying the signal to the terminals of the battery includes measuring the first terminal voltage at an end of the first pulse of the signal.

8. The method of claim 1 wherein:

the second terminal voltage is a value which is a predetermined percentage of the first terminal voltage, and

calculating data which is representative of the overpotential of the battery further includes using (i) characteristics of a decay of the terminal voltage of the battery associated with the battery and (ii) an amount of time for the terminal voltage of the battery to decay to the second terminal voltage of the battery.

9. The method of claim 1 wherein calculating data which is representative of the overpotential of the battery further includes using (i) an amount of time for the terminal voltage of the battery to decay from the first terminal voltage of the battery to the second terminal voltage of the battery and (ii) a rate of change of the terminal voltage of the battery after terminating the signal.

10. The method of claim 9 wherein the rate of change of the terminal voltage in response to terminating the first pulse of the signal corresponds to the square root of time.

11. The method of claim 1 wherein the second terminal voltage is a voltage at which the overpotential is capable of being determined based on or using a form, shape or rate of decay of the terminal voltage of the battery after terminating the first pulse of the signal.

29. The method of claim 1 wherein determining data which is representative of a state of charge of the battery includes using data which is representative of:

(i) the overpotential of the battery and (ii) a terminal voltage of the battery.

30. The method of claim 29 wherein outputting the data which is representative of the state of charge of the battery includes displaying the data which is representative of the state of charge of the battery.

31. The method of claim 29 wherein the first pulse is a charge current pulse or a discharge current pulse.

32. The method of claim 1 further including determining the equilibrium voltage of the battery using the second terminal voltage and characteristics of a decay of the terminal voltage after applying the first pulse of the signal to the terminals of the battery and wherein calculating data which is representative of the overpotential of the battery uses the first terminal voltage of the battery and the equilibrium voltage of the battery.

33. The method of claim 1 further including determining the equilibrium voltage of the battery using characteristics of a rate of change of the terminal voltage after applying the first pulse of the signal to the terminals of the battery and wherein calculating data which is representative of the overpotential of the battery uses the first terminal voltage of the battery and the equilibrium voltage of the battery.

34. The method of claim 1 wherein the second terminal voltage is a voltage at which the overpotential is capable of being determined using a shape or rate of decay of the terminal voltage of the battery after terminating the first pulse of the signal.

12-28. -28. (canceled)