Battery adaptive charging
Systems and apparatus may carry out analysis of battery physical phenomena, and characterize batteries based on phenomena occurring in particular time and/or frequency domains. These systems may be additionally responsible for charging and/or monitoring a rechargeable battery. Examples of battery physical phenomena include mass transport (e.g., diffusion and/or migration) in battery electrolytes, mass transport in battery electrodes, and reactions on battery electrodes.
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) determining the battery's partial relaxation time, peak amplitude of a voltage change, full relaxation time, overpotential, available stored charge, and/or impedance;
(b) based on the battery's partial relaxation time, peak amplitude of a voltage change, full relaxation time, overpotential, available stored charge, and/or impedance determined in (a), determining that a state of health of the battery has decreased over time or use of the battery; and
(c) based at least in part on the battery's state of health having decreased, lowering a charge current applied to the battery during a charging process for the battery.
2. The method of claim 1 , wherein lowering a charge current applied to the battery during a charging process for the battery comprises changing an amplitude and/or duration of charge current applied to the battery during the charging process.
3. The method of claim 1 , wherein lowering a charge current applied to the battery during a charging process for the battery comprises applying a plurality of charge signals that decrease in magnitude over time.
4. The method of claim 1 , wherein lowering a charge current applied to the battery during a charging process for the battery comprises applying a plurality of charge steps that decrease in magnitude over time.
5. The method of claim 1 , wherein lowering the charge current applied to the battery during a charging process for the battery comprises adjusting a peak charging current.
6. The method of claim 1 , wherein lowering the charge current applied to the battery during a charging process for the battery comprises adjusting the charging process to reduce the terminal voltage of the battery, during the charging process, to a level below a predetermined value and/or a predetermined range.
7. The method of claim 1 , wherein the state of health is representative of an ability of the battery to hold a charge.
8. The method of claim 1 , wherein the state of health is representative of a maximum charge capacity of the battery.
9. The method of claim 1 , wherein determining that a state of health of the battery has decreased over time or use of the battery comprises determining that the battery aged, deteriorated, and/or degraded.
10. The method of claim 1 , wherein determining that a state of health of the battery has decreased over time or use of the battery comprises determining a shift in a voltage-charge curve of the battery.
11. The method of claim 1 , wherein determining that a state of health of the battery has decreased over time or use of the battery comprises determining an impedance and/or a change of impedance of the battery.
12. The method of claim 1 , wherein determining that a state of health of the battery has decreased over time or use of the battery comprises using a correlation or relationship between the state of health of the battery and an impedance of the battery and/or a change of impedance of the battery.
13. The method of claim 1 , wherein determining that a state of health of the battery has decreased over time or use of the battery comprises using a correlation or relationship between the state of health of the battery and an impedance of the battery over one or more charge and/or discharge cycles.
14. The method of claim 1 , wherein the battery comprises a plurality of cells.
15. A system for charging a battery including at least two terminals, the system comprising:
charging and/or monitoring circuitry designed or configured to apply a charge signal to the battery; and
control circuitry, coupled to the charging and/or monitoring circuitry designed or configured to cause the system to:
(a) determine the battery's partial relaxation time, peak amplitude of a voltage change, full relaxation time, overpotential, available stored charge, and/or impedance;
(b) based on the battery's partial relaxation time, peak amplitude of a voltage change, full relaxation time, overpotential, available stored charge, and/or impedance determined in (a), determine that a state of health of the battery has decreased over time or use of the battery; and
(c) based at least in part on the battery's state of health having decreased, lower a charge current applied to the battery during a charging process for the battery.
16. The system of claim 15 , wherein lowering a charge current applied to the battery during a charging process for the battery comprises changing an amplitude and/or duration of charge current applied to the battery during the charging process.
17. The system of claim 15 , wherein lowering a charge current applied to the battery during a charging process for the battery comprises applying a plurality of charge signals that decrease in magnitude over time.
18. The system of claim 15 , wherein lowering a charge current applied to the battery during a charging process for the battery comprises applying a plurality of charge steps that decrease in magnitude over time.
19. The system of claim 15 , wherein lowering the charge current applied to the battery during a charging process for the battery comprises adjusting a peak charging current.
20. The system of claim 15 , wherein lowering the charge current applied to the battery during a charging process for the battery comprises adjusting the charging process to reduce the terminal voltage of the battery, during the charging process, to a level below a predetermined value and/or a predetermined range.
21. The system of claim 15 , wherein the state of health is representative of an ability of the battery to hold a charge.
22. The system of claim 15 , wherein the state of health is representative of a maximum charge capacity of the battery.
23. The system of claim 15 , wherein determining that a state of health of the battery has decreased over time or use of the battery comprises determining that the battery aged, deteriorated, and/or degraded.
24. The system of claim 15 , wherein determining that a state of health of the battery has decreased over time or use of the battery comprises determining a shift in a voltage-charge curve of the battery.
25. The system of claim 15 , wherein determining that a state of health of the battery has decreased over time or use of the battery comprises determining an impedance and/or a change of impedance of the battery.
26. The system of claim 15 , wherein determining that a state of health of the battery has decreased over time or use of the battery comprises using a correlation or relationship between the state of health of the battery and an impedance of the battery and/or a change of impedance of the battery.
27. The system of claim 15 , wherein determining that a state of health of the battery has decreased over time or use of the battery comprises using a correlation or relationship between the state of health of the battery and an impedance of the battery over one or more charge and/or discharge cycles.
28. The system of claim 15 , wherein the battery comprises a plurality of cells.