Method and circuitry to adaptively charge a battery/cell using the state of health thereof

• US 10,067,198 B2
• Filed: 06/26/2015
• Issued: 09/04/2018
• Est. Priority Date: 05/21/2010
• Status: Active Grant

• Current Assignee: Qnovo, Inc.
• Original Assignee: Qnovo, Inc.
• Inventors: Maluf, Nadim, Ghantous, Dania, Berkowitz, Fred, Peabody, Christina
• Primary Examiner(s): Pacheco, Alexis
• Application Number:
  US14/752,592
• Publication Number:
  US 20150377976A1
• Time in Patent Office: 1,166 Days
• Field of Search: 320139, 320141, 320129, 320145, 320151, 320137, 320148, 320157, 320125, 320133, 320127, 320128, 320155, 320156, 324426, 324427, 324429
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• 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: 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 7/005 Detection of state of health [SOH]
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The present inventions, in one aspect, are directed to techniques and/or circuitry to determining data which is representative of the state of health, or a change therein, of the battery using the data which is representative of (i) the relaxation time of the battery and/or (ii) the overpotential of the battery. In another aspect the present inventions are directed to techniques and/or circuitry to adapt one or more characteristics of a charge signal using data which is representative of the state of health, or a change therein, of the battery. In yet another aspect the present inventions are directed to techniques and/or circuitry to determine a state of charge of the battery using data which is representative of the state of health, or a change therein, of the battery.

Claims

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

(a) applying a signal to at least two terminals of the battery, wherein the signal injects charge into the battery;

(b) measuring a terminal voltage between terminals of the battery at a predetermined time relative to applying to the signal;

(c) from the measurements of the terminal voltage in (b), determining a state of health of the battery or a change therein, wherein the state of health is representative of degradation of the battery and/or an ability of the battery to hold a charge; and

(d) adapting one or more characteristics of a charging process for the battery, using the determined state of health of the battery, or a change therein.

2. The method of claim 1, wherein:

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

adapting one or more characteristics of the charging process includes changing (i) an amount of time between pulses of temporally successive charge packets of the plurality of charge packets and/or (ii) an amplitude and/or duration of the at least one pulse of a charge packet of the plurality of charge packets.

3. The method of claim 1, wherein:

the charging process includes supplying a plurality of charge packets to the battery terminals, wherein each charge packet includes at least one charge pulse and at least one discharge pulse, and

adapting one or more characteristics of the signal further includes adapting an amplitude and/or pulse width of at least one charge pulse and/or at least one discharge pulse of at least one charge packet.

4. The method of claim 1, further comprising determining a state of charge of the battery using data which is representative of the state of health, or a change therein, of the battery.

5. The method of claim 4, further comprising:

correlating the data which is representative of the state of health, or a change therein, to a first relationship between an open circuit voltage and an amount of charge in the battery;

calculating an open circuit voltage of the battery using a terminal voltage of the battery, a current applied to or removed from the battery, and an impedance of the battery; and

determining the state of charge of the battery using (i) the calculated open circuit voltage and (ii) the first relationship of the open circuit voltage to the amount of charge in the battery.

6. The method of claim 1, further comprising determining the equilibrium voltage of the battery using characteristics of a decay of the terminal voltage associated with the battery.

7. The method of claim 1, further comprising using the measured terminal voltages to calculate information representing an overpotential of the battery, a relaxation time of the battery, and/or a partial relaxation time of the battery.

8. The method of claim 7, wherein the relaxation time is an amount of time corresponding to when, in response to a pulse of the signal, the terminal voltage of the battery decays to at least a predetermined voltage.

9. The method of claim 8, wherein the predetermined voltage is a voltage which is constant or substantially constant after applying the pulse of the signal and before applying another and immediately subsequent pulse of the signal.

10. The method of claim 8, wherein the predetermined voltage is a voltage at which the relaxation time is capable of being determined using a form, shape and/or rate of decay of the voltage at the terminals of the battery due to the pulse of the signal.

11. The method of claim 1, wherein measuring the terminal voltage comprises:

(i) measuring a first terminal voltage of the battery at a first predetermined time relative to applying the signal to the terminals of the battery; and

(ii) monitoring the terminal voltage of the battery after applying 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.

12. The method of claim 11, further comprising calculating data representative of an overpotential of the battery using the first terminal voltage of the battery and the second terminal voltage of the battery,

wherein determining the state of health of the battery or a change therein uses the data which is representative of the overpotential of the battery.

13. The method of claim 12, wherein calculating data which is representative of the overpotential of the battery further comprises using

(i) characteristics of a decay of the terminal voltage of 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.

14. An apparatus to charge a battery including at least two terminals, the apparatus comprising:

charging circuitry, coupled to the battery, to;

generate a signal, and

apply the signal to the battery;

monitoring circuitry, coupled to the battery, to measure a voltage at the terminals of the battery; and

control circuitry, coupled to the charging circuitry and the monitoring circuitry, and configured to;

(a) apply the signal to at least two terminals of the battery, wherein the signal injects charge into the battery;

(b) measure a terminal voltage between terminals of the battery at a predetermined time relative to applying to the signal;

(c) from the measurements of the terminal voltage in (b), determine a state of health of the battery or a change therein, wherein the state of health is representative of degradation of the battery and/or an ability of the battery to hold a charge; and

(d) adapting one or more characteristics of a charging process for the battery based on the determined state of health of the battery, or a change therein.

15. The apparatus of claim 14, wherein:

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

the control circuitry is configured to adapt one or more characteristics of the charging process by changing (i) an amount of time between pulses of temporally successive charge packets of the plurality of charge packets and/or (ii) an amplitude and/or duration of the at least one pulse of a charge packet of the plurality of charge packets.

16. The apparatus of claim 14, wherein:

the signal 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 is configured to adapt one or more characteristics of the charging process by adapting an amplitude and/or pulse width of at least one charge pulse and/or at least one discharge pulse of at least one charge packet.

17. The apparatus of claim 14, wherein the control circuitry is further configured to determine a state of charge of the battery using data which is representative of the state of health, or a change therein, of the battery.

18. The apparatus of claim 17, wherein the control circuitry is further configured to:

correlate the data which is representative of the state of health, or a change therein, to a first relationship between an open circuit voltage and an amount of charge in the battery;

calculate an open circuit voltage of the battery using a terminal voltage of the battery, a current applied to or removed from the battery, and an impedance of the battery; and

determine the state of charge of the battery using (i) the calculated open circuit voltage and (ii) the first relationship of the open circuit voltage to the amount of charge in the battery.

19. The apparatus of claim 14, wherein the control circuitry is further configured to determine the equilibrium voltage of the battery using characteristics of a decay of the terminal voltage associated with the battery.

20. The apparatus of claim 14, wherein the control circuitry is further configured to use the measured terminal voltages to calculate information representing an overpotential of the battery, a relaxation time of the battery, and/or a partial relaxation time of the battery.

21. The apparatus of claim 20, wherein the relaxation time is an amount of time corresponding to when, in response to a pulse of the signal, the terminal voltage of the battery decays to at least a predetermined voltage.

22. The apparatus of claim 21, wherein the predetermined voltage is a voltage which is constant or substantially constant after applying the pulse of the signal and before applying another and immediately subsequent pulse of the signal.

23. The apparatus of claim 21, wherein the predetermined voltage is a voltage at which the relaxation time is capable of being determined using a form, shape and/or rate of decay of the voltage at the terminals of the battery due to the pulse of the signal.

24. The apparatus of claim 14, wherein the monitoring circuitry is configured to:

(i) measure a first terminal voltage of the battery at a first predetermined time relative to applying the signal to the terminals of the battery; and

(ii) monitor the terminal voltage of the battery after applying 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.

25. The apparatus of claim 24, wherein the control circuitry is further configured to

calculate data representative of an overpotential of the battery using the first terminal voltage of the battery and the second terminal voltage of the battery,

determine the state of health of the battery or a change therein by using the data which is representative of the overpotential of the battery.

26. The apparatus of claim 25, wherein the control circuitry is further configured to calculate the data which is representative of the overpotential of the battery by using

(i) characteristics of a decay of the terminal voltage of 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.