Method For Determining Battery Capacity

• US 20100117657A1
• Filed: 01/19/2010
• Published: 05/13/2010
• Est. Priority Date: 11/05/2004
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Fu, Runbo, Ahmed, Farhad
• Granted Patent: US 8,010,305 B2
• Time in Patent Office: Days
• US Class Current: 324/427
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass
• 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: Y02E 60/10 Energy storage using batteries

Abstract

An electrical device is powered by a battery. The device includes transition phase determining circuitry operatively connected to the battery to determine that the battery has entered a transition phase based on the occurrence of a change in direction of current flowing through the battery. Battery capacity determining circuitry is operatively connected to the transition phase determining circuitry and configured to determine, in response the transition phase determining circuitry determining that the battery is in the transition phase, a capacity of the battery based on a transition phase battery capacity model of capacity-vs.-voltage. The transition phase determining circuitry is further configured to determine an end of the transition phase based on the transition phase battery capacity model and a non-transition battery capacity model of capacity-vs.-voltage yielding the same capacity value for a given measured voltage of the battery.

Claims

1. An electrical device powered by a battery, comprising:

transition phase determining circuitry operatively connected to the battery to determine that the battery has entered a transition phase based on the occurrence of a change in direction of current flowing through the battery; and

battery capacity determining circuitry operatively connected to the transition phase determining circuitry and configured to determine, in response the transition phase determining circuitry determining that the battery is in the transition phase, a capacity of the battery based on a transition phase battery capacity model of capacity-vs.-voltage;

the transition phase determining circuitry being further configured to determine an end of the transition phase based on the transition phase battery capacity model and a non-transition battery capacity model of capacity-vs.-voltage yielding the same capacity value for a given measured voltage of the battery.

2. The electrical device of claim 1 wherein the transition phase determining circuitry is further configured to determine the end of the transition phase based on a lapse of a predetermined time period from the start of the transition phase.

3. The electrical device of claim 1 wherein the transition phase determining circuitry is further configured to determine the end of the transition phase based on the voltage of the battery having changed by a predetermined voltage value.

4. The electrical device of claim 1 wherein the electrical device is a mobile communication device.

5. An electrical device powered by a battery, comprising:

voltage reading circuitry configured to monitor the output voltage of a power source that is charging the battery;

transition phase determining circuitry operatively connected to the voltage reading circuitry to determine that the battery has entered a transition phase based on sensing an abrupt change in the output voltage; and

battery capacity determining circuitry configured to determine, in response to the transition phase determining circuitry determining that the battery is in the transition phase, a capacity of the battery based on a transition phase battery capacity model;

wherein the transition phase battery capacity model is determined from both a non-transition battery capacity charge model and a non-transition battery capacity discharge model, all three models defining the battery'"'"'s capacity as a function of its voltage.

6. The electrical device of claim 5 wherein the abrupt change is from 0V to a predetermined voltage value or from a predetermined voltage value to 0V.

7. An electrical device powered by a battery, comprising:

transition phase determining circuitry operatively connected to the battery to determine that the battery has entered a transition phase that is initiated by a change in direction of current through the battery; and

battery capacity determining circuitry configured to determine, in response to the transition phase determining circuitry determining that the battery is in the transition phase, a capacity of the battery based on a transition phase battery capacity model;

the transition phase determining circuitry being further configured to determine that the transition phase has ended based on the lapse of a predetermined time period from the start of the transition phase; and

the transition phase battery capacity model being determined from both a non-transition battery capacity charge model and a non-transition battery capacity discharge model, all three models defining the battery'"'"'s capacity as a function of its voltage.

8. An electrical device powered by a battery, comprising:

transition phase determining circuitry operatively connected to the battery to determine that the battery has entered a transition phase initiated by a change in direction of current through the battery; and

battery capacity determining circuitry configured to determine, in response to the transition phase determining circuitry determining that the battery is in the transition phase, a capacity of the battery based on a transition phase battery capacity model;

the transition phase determining circuitry being further configured to determine that the transition phase has ended based on the battery voltage having changed by a predetermined voltage value from the battery voltage at the start of the transition phase; and

the transition phase battery capacity model being determined from both a non-transition battery capacity charge model and a non-transition battery capacity discharge model, all three models defining capacity as a function of voltage for the battery.

9. An electrical device powered by a battery, comprising:

transition phase determining circuitry configured to determine that the battery has entered a transition phase initiated by a change in direction of current through the battery; and

voltage reading circuitry operatively connected to the battery to measure a voltage of the battery;

the transition phase determining circuitry being further configured to determine the end of the transition phase based on a transition phase battery capacity model of capacity-vs.-voltage and a non-transition battery capacity model of capacity-vs.-voltage yielding the same capacity value for the voltage measured by the voltage reading circuitry.

10. An electrical device powered by a battery, comprising:

circuitry for selecting a transition phase battery capacity model from a plurality of transition phase battery capacity models that are determined from both a non-transition battery capacity charge model and a non-transition battery capacity discharge model, all three models defining the battery'"'"'s capacity as a function of its voltage, and a capacity value of the transition phase model for a each given voltage being calculated based on a weighted average of two capacity values yielded by the two non-transition models for the given voltage; and

battery capacity determining circuitry for using the transition phase model to determine capacity of the battery.

11. The electrical device of claim 10 wherein a weighting factor for the weighted average is based on (V−

Vstart)/(Vend−

Vstart), where V is the given voltage, and Vstart and Vend are the measured voltages of the battery at the start and end, respectively, of the transition phase.

12. The electrical device of claim 10 wherein each capacity value of the transition phase model is calculated based on both the weighted average and an offset value based on temperature of the battery.

13. An electrical device powered by a battery, comprising:

voltage reading circuitry configured to monitor the voltage of a power source connector that is charging the battery;

transition phase determining circuitry operatively connected to the voltage reading circuitry to determine that the battery has entered a transition phase based on sensing an abrupt change in the voltage; and

battery capacity determining circuitry configured to determine, in response to the transition phase determining circuitry determining that the battery is in the transition phase, a capacity of the battery based on a transition phase battery capacity model that defines the battery'"'"'s capacity as a function of the battery'"'"'s voltage;

the transition phase occurring upon connection of the battery to a power source or disconnection of the battery from a power source, in which the battery'"'"'s capacity as a function of voltage differs from both a charge curve and a discharge curve of the battery.

14. The electrical device of claim 13 wherein the transition phase determining circuitry is configured to determine that the battery has entered a transition phase from discharging to charging based on sensing an abrupt increase in the connector voltage.

15. The electrical device of claim 13 wherein the transition phase determining circuitry is configured to determine that the battery has entered a transition phase from charging to discharging based on sensing an abrupt decrease in the connector voltage.

16. The electrical device of claim 13 wherein the abrupt change is from 0V to a predetermined voltage value or from a predetermined voltage value to 0V.

17. The electrical device of claim 13 wherein the transition phase determining circuitry is configured to determine that the transition phase has ended based on the lapse of a predetermined time period from the start of the transition phase.

18. The electrical device of claim 13 wherein the transition phase determining circuitry is configured to determine that the transition phase has ended based on the battery'"'"'s voltage having changed by a predetermined voltage value from the battery'"'"'s voltage at the start of the transition phase.

19. The electrical device of claim 13 wherein the transition phase battery capacity model is determined from both a non-transition battery capacity charge model and a non-transition battery capacity discharge model, all three models defining the battery'"'"'s capacity as a function of the battery'"'"'s voltage.

20. The electrical device of claim 13 wherein the electrical device is a mobile communication device.

21. An electrical device powered by a battery, comprising:

transition phase determining circuitry operatively connected to the battery to determine that the battery has entered a transition phase initiated by a change in direction of current through the battery; and

battery capacity determining circuitry configured to determine, in response to the transition phase determining circuitry determining that the battery is in the transition phase, a capacity of the battery based on a transition phase battery capacity model that defines the battery'"'"'s capacity as a function of the battery'"'"'s voltage;

the transition phase determining circuitry being further configured to determine that the transition phase has ended based on the lapse of a predetermined time period from the start of the transition phase; and

the transition phase occurring upon connection of the battery to a power source or disconnection of the battery from a power source, in which the battery'"'"'s capacity as a function of voltage differs from both a charge curve and a discharge curve of the battery.

22. The electrical device of claim 21 wherein the battery capacity determining circuitry is further configured to cease to base the capacity determination on the transition phase battery capacity model, in response to the transition phase determining circuitry determining the end of the transition phase.

23. The electrical device of claim 21 wherein the battery capacity determining circuitry is further configured to determine the battery capacity based on a non-transition phase battery capacity model, in response to the transition phase determining circuitry determining the end of the transition phase.

24. The electrical device of claim 21 wherein the electrical device is a mobile communication device.

25. An electrical device powered by a battery, comprising:

transition phase determining circuitry operatively connected to the battery to determine that the battery has entered a transition phase initiated by a change in direction of current through the battery; and

battery capacity determining circuitry configured to determine, in response to the transition phase determining circuitry determining that the battery is in the transition phase, a capacity of the battery based on a transition phase battery capacity model that defines the battery'"'"'s capacity as a function of the battery'"'"'s voltage;

the transition phase determining circuitry being further configured to determine that the transition phase has ended based on the battery voltage having changed by a predetermined voltage value from the battery voltage at the start of the transition phase; and

the transition phase occurring upon connection of the battery to a power source or disconnection of the battery from a power source, in which the battery'"'"'s capacity as a function of voltage differs from both a charge curve and a discharge curve of the battery.

26. The electrical device of claim 25 wherein the battery capacity determining circuitry is further configured to cease to base the capacity determination on the transition phase battery capacity model, in response to the transition phase determining circuitry determining the end of the transition phase.

27. The electrical device of claim 25 wherein the battery capacity determining circuitry is further configured to determine the battery capacity based on a non-transition phase battery capacity model, in response to the transition phase determining circuitry determining the end of the transition phase.

28. The electrical device of claim 25 wherein the electrical device is a mobile communication device.

29. An electrical device powered by a battery, comprising:

circuitry for selecting a transition phase battery capacity model that is a function of both a non-transition battery capacity charge model and a non-transition battery capacity discharge model, all three models defining the battery'"'"'s capacity as a function of its voltage;

the transition phase occurring upon connection of the battery to a power source or disconnection of the battery from a power source, in which the battery'"'"'s capacity as a function of voltage differs from both a charge curve and a discharge curve of the battery.

30. The electrical device of claim 29 wherein the capacity value of the transition phase model for each given voltage is a function of the two capacity values yielded by the two non-transition models for the given voltage.

31. The electrical device of claim 29 further comprising battery capacity determining circuitry configured to use the transition phase model to determine capacity of the battery.

32. An electrical device powered by a battery, comprising:

state determining circuitry configured to determine if the battery is in a charging state, a discharging state, or a transition phase, the transition phase occurring upon connection of the battery to a power source or disconnection of the battery from a power source, in which the battery'"'"'s capacity as a function of voltage differs from both a charge curve and a discharge curve of the battery; and

battery capacity determining circuitry configured to;

determine the battery'"'"'s capacity through the battery'"'"'s charge capacity model as a function of voltage if the battery is in the charging state;

determine the battery'"'"'s capacity through the battery'"'"'s discharge capacity model as a function of voltage if the battery is in the discharging state, then; and

determine the battery'"'"'s capacity through a transition capacity model as a function of voltage if the battery is in the transition phase.

33. The electrical device of claim 32 wherein the state determining circuitry is configured to determine that the battery has entered the transition phase based on sensing an abrupt change in the battery'"'"'s voltage.

34. The electrical device of claim 33 wherein the state determining circuitry is configured to determine that the battery has entered the transition phase based on sensing a change in direction of current through the battery.

35. The electrical device of claim 33 wherein a capacity value of the transition phase model for each given voltage is calculated as function of two capacity values yielded by the charge model and discharge model for the given voltage.