Method and circuitry to adaptively charge a battery/cell

• US 8,513,921 B2
• Filed: 02/14/2013
• Issued: 08/20/2013
• Est. Priority Date: 06/24/2010
• Status: Active Grant

• Current Assignee: Qnovo, Inc.
• Original Assignee: Qnovo, Inc.
• Inventors: Berkowitz, Fred, Maluf, Nadim, Ghantous, Dania
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US13/767,839
• Publication Number:
  US 20130154548A1
• Time in Patent Office: 187 Days
• Field of Search: 320/107, 320/132, 320/133, 320/134, 320/139, 320/141
• US Class Current: 320/141
• 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 adapt the charging 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 calculate data which is representative of an overpotential of the battery/cell.

Claims

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

applying a charge signal to the at least two terminals of the battery, wherein the charge signal includes a plurality of pulses;

measuring a plurality of voltages between the at least two terminals of the battery, wherein measuring the plurality of voltages includes measuring;

a first voltage between the at least two terminals of the battery, which is in response to a first pulse of the charge signal and at a first predetermined time relative to applying the first pulse to the at least two terminals of the battery, and

a second voltage between the at least terminals of the battery after applying the first pulse wherein the second voltage is a voltage which correlates to an equilibrium voltage of the battery, wherein equilibrium voltage of the battery corresponds to a voltage between the at least two terminals of the battery which is substantially constant when no charging current is applied to the at least two terminals of the battery;

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

adapting one or more characteristics of the charge signal based on or using data which is representative of the overpotential of the battery.

2. The method of claim 1 further including:

determining whether the overpotential of the battery exceeds a predetermined value; and

wherein adapting one or more characteristics of the charge signal further includes adapting one or more characteristics of the charge signal if the overpotential of the battery exceeds the predetermined value.

3. The method of claim 2 wherein the predetermined value changes during charging of the battery in accordance with a change in a state of charge of the battery or a state of health of the battery.

4. The method of claim 2 wherein the predetermined value changes during charging of the battery in accordance with a change in a state of charge of the battery and a state of health of the battery.

5. The method of claim 1 wherein the second voltage corresponds to a voltage between the at least two terminals of the battery which is substantially constant when no charging current is applied to the terminals of the battery.

6. The method of claim 1 further including:

determining the equilibrium voltage of the battery using (i) the second voltage and (ii) characteristics of a decay of a voltage between the at least two terminals which is associated with the battery.

7. The method of claim 1 wherein the first predetermined time relative to applying the first pulse of charge signal to the terminals of the battery corresponds to immediately before, at a beginning of or at an end of the first pulse of the charge signal.

8. The method of claim 1 wherein:

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

calculating data which is representative of the overpotential of the battery further includes using (i) characteristics of a decay of the voltage between the at least two terminals of the battery and (ii) an amount of time for the voltage between the at least two terminals of the battery to decay to the second voltage.

9. The method of claim 1 wherein calculating data which is representative of the overpotential of the battery further includes using:

an amount of time for the voltage between the at least two terminals of the battery to decay from the first voltage to the second voltage, and

a rate of change of the voltage between the at least two terminals of the battery after applying the first pulse of the charge signal to the terminals of the battery.

10. The method of claim 9 wherein the rate of change of the voltage between the at least two terminals of the battery corresponds to the square root of time.

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

12. The method of claim 1 wherein:

the charge signal further includes a plurality of charge packets, wherein each charge packet includes at least one pulse, and

adapting one or more characteristics of the charge signal includes changing the amount of time between pulses of temporally successive charge packets of the plurality of charge packets based on or using data which is representative of the overpotential of the battery.

13. The method of claim 1 wherein:

the charge signal further includes a plurality of charge packets, wherein each charge packet includes at least one pulse, and

adapting one or more characteristics of the charge signal includes changing the amplitude of the at least one pulse of a charge packet of the plurality of charge packets based on or using data which is representative of the overpotential of the battery.

14. The method of claim 1 wherein:

applying a charge signal to the terminals of the battery further includes applying a plurality of charge packets, wherein each charge packet includes at least one charge pulse and at least one discharge pulse, and

adapting one or more characteristics of the charge signal further includes adapting the amplitude of the at least one charge pulse or at least one discharge pulse of each charge packet based on data which is representative of the overpotential of the battery.

15. The method of claim 1 wherein:

applying a charge signal to the terminals of the battery further includes applying a plurality of charge packets, wherein each charge packet includes at least one charge pulse and at least one discharge pulse, and

adapting one or more characteristics of the charge signal further includes adapting the pulse width of the at least one charge pulse or the at least one discharge pulse of a charge packet based on data which is representative of the overpotential of the battery.

16. The method of claim 1 further including:

determining the equilibrium voltage of the battery using;

(i) the second voltage and (ii) characteristics of a decay of the voltage between the at least two terminals after applying the first pulse of the charge signal to the terminals of the battery, and

wherein calculating data which is representative of an overpotential of the battery further includes using the equilibrium voltage of the battery.

17. The method of claim 1 further including:

determining the equilibrium voltage of the battery using;

(i) the second voltage and (ii) characteristics of a rate of change of the voltage between the at least two terminals after applying the first pulse of the charge signal to the terminals of the battery, and

wherein calculating data which is representative of an overpotential of the battery further includes using the equilibrium voltage of the battery.

18. An apparatus to adaptively charge a battery, wherein the battery includes at least two terminals, the apparatus comprising:

charge circuitry, coupled to the battery, to generate a charge signal and apply the charge signal to the at least two terminals of the battery, wherein the charge signal includes a plurality of pulses;

measurement circuitry, coupled to the battery, to measure a plurality of voltages between the at least two terminals of the battery, and wherein the measurement circuitry measures;

a first voltage between the at least two terminals of the battery, which is in response to a first pulse of the charge signal and at a first predetermined time relative to applying the first pulse of charge signal to the at least two terminals of the battery, and

a second voltage between the at least two terminals of the battery after applying the first pulse wherein the second voltage is a voltage which correlates to an equilibrium voltage of the battery, wherein equilibrium voltage of the battery corresponds to a voltage which is substantially constant when no charging current is applied to the at least two terminals of the battery; and

control circuitry which is coupled to the measurement circuitry and charge circuitry, wherein the control circuitry is configured to;

calculate data which is representative of an overpotential of the battery using the first and second voltages, and

adapt one or more characteristics of the charge signal using the data which is representative of the overpotential of the battery by generating and outputting one or more control signals.

19. The apparatus of claim 18 wherein the first predetermined time relative to applying the first pulse of charge signal to the at least two terminals of the battery corresponds to immediately before, at a beginning of or at an end of the first pulse of the charge signal.

20. The apparatus of claim 18 wherein the second voltage corresponds to a voltage between the at least two terminals of the battery which is substantially constant after applying the first pulse to the terminals of the battery and when no charging current is applied to the at least two terminals of the battery.

21. The apparatus of claim 18 wherein the first pulse of the charge signal is a charge pulse or a discharge pulse.

22. The apparatus of claim 18 wherein the control circuitry calculates:

(i) the equilibrium voltage using the second voltage and characteristics of a decay of the voltage between the at least two terminals of the battery and (ii) the data which is representative of the overpotential of the battery using the equilibrium voltage of the battery.

23. The apparatus of claim 22 wherein the first pulse of the charge signal is a charge pulse or a discharge pulse.

24. The apparatus of claim 18 wherein:

the charge signal further includes a plurality of charge packets, wherein each charge packet includes at least one charge pulse and/or at least one discharge pulse, and

the control circuitry;

determines whether the overpotential of the battery is within a predetermined range or greater than a predetermined value, and

if the overpotential exceeds the predetermined range or is greater than the predetermined value, the control circuitry generates the one or more control signals to change one or more characteristics of the charge packets of the charge signal.

25. The apparatus of claim 24 wherein the predetermined range or the predetermined value changes during charging of the battery in accordance with changes in a state of charge of the battery.

26. The apparatus of claim 24 wherein the predetermined range or the predetermined value changes during charging of the battery in accordance with changes in a state of health of the battery.

27. The apparatus of claim 18 wherein:

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

the control circuitry calculates the data which is representative of an overpotential of the battery using (i) characteristics of a decay of the voltage between the at least two terminals of the battery and (ii) an amount of time for the voltage between the at least two terminals of the battery to decay to the second voltage of the battery.

28. The apparatus of claim 18 wherein:

the control circuitry calculates data which is representative of the overpotential of the battery using (i) an amount of time for the voltage between the at least two terminals of the battery to decay from the first voltage to the second voltage and (ii) a rate of change of the voltage between the at least two terminals of the battery, and

the rate of change of the voltage between the at least two terminals of the battery corresponds to the square root of time.

29. The apparatus of claim 18 wherein:

the charge signal further includes a plurality of charge packets, wherein each charge packet includes at least one charge pulse and at least one discharge pulse, and

the control circuitry changes the amount of time between pulses of temporally successive charge packets of the plurality of charge packets based on or using data which is representative of the overpotential of the battery.

30. The apparatus of claim 18 wherein:

the charge signal further includes a plurality of charge packets, wherein each charge packet includes at least one charge pulse and at least one discharge pulse, and

the control circuitry changes the amplitude of at least one of the at least one charge pulse or the at least one discharge pulse of a charge packet of the plurality of charge packets based on or using data which is representative of the overpotential of the battery.