Method of estimating remaining constant current/constant voltage charging time

• US 8,712,708 B2
• Filed: 10/25/2010
• Issued: 04/29/2014
• Est. Priority Date: 10/25/2010
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Nokia Corporation
• Inventors: Halme, Matti Samuli
• Primary Examiner(s): CHERRY, STEPHEN J
• Application Number:
  US12/911,075
• Publication Number:
  US 20120101754A1
• Time in Patent Office: 1,282 Days
• Field of Search: 702/63
• US Class Current: 702/63
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]

Abstract

Method, apparatus, and computer program product embodiments are disclosed for estimating the remaining charging time of a rechargeable battery. An example embodiment of the invention comprises a method comprising the steps of determining if the battery charging point is in a constant current phase or in a constant voltage phase; if the battery charging point is in the constant current phase, calculating a time remaining to charge in the constant current phase based on the constant current phase charging characteristics and a time remaining to charge in the constant voltage phase based on the constant voltage phase charging characteristics; and if the battery charging point is in the constant voltage phase, calculating a time remaining to charge in the constant voltage phase based on the constant voltage phase charging characteristics.

Claims

1. A method, comprising:

detecting, by an apparatus, an availability of a charger adapter;

determining, by the apparatus, whether a battery charging point is in a constant current phase or in a constant voltage phase, based on pre-determined battery charging characteristics, wherein the pre-determined battery charging characteristics comprise constant current phase charging characteristics and constant voltage phase charging characteristics;

calculating, by the apparatus, a time remaining to charge in the constant current phase based on the constant current phase charging characteristics, if the battery charging point is in the constant current phase; and

calculating, by the apparatus, a time remaining to charge in the constant voltage phase based on the constant voltage phase charging characteristics, if the battery charging point is in the constant voltage phase;

wherein the time remaining to charge in the constant current phase is based on stored charge characteristics in the constant current phase, when the battery charging point is in the constant current phase and wherein battery stored charge characteristics comprises a battery stored charge value based on monitored tracking of battery charging and discharging.

2. The method of claim 1, wherein the battery stored charge characteristics comprise data that provides a remaining charging time estimate based on a battery stored charge estimate.

3. The method of claim 1, wherein the time remaining to charge in the constant current phase comprises a pre-measured duration to account for the constant voltage phase that follows the constant current phase, when the battery charging point is in the constant current phase.

4. The method of claim 1, wherein the time remaining to charge in the constant voltage phase is based on charging current characteristics in the constant voltage phase, when the battery charging point is in the constant voltage phase.

5. The method of claim 1, further comprising:

identifying, by the apparatus, a correct category of the charger adapter after detecting its availability; and

configuring, by the apparatus, battery charging based in the category of the charger adapter.

6. The method of claim 1, further comprising:

identifying, by the apparatus, a correct category of the charger adapter after detecting its availability; and

using, by the apparatus, the category of the charger adapter to improve accuracy of an initial remaining charging time estimation.

7. The method of claim 1, further comprising:

calculating, by the apparatus, a time remaining to charge in the constant current phase based on the constant current phase charging characteristics and a time remaining to charge in the constant voltage phase based on the constant voltage phase charging characteristics, if the battery charging point is in the constant current phase.

8. The method of claim 1, further comprising:

correcting, by the apparatus, the time remaining to charge in the constant current phase by a ratio of charging current measured in the pre-determined battery charging characteristics and an actual present charging current.

9. The method of claim 1, further comprising:

correcting, by the apparatus, the time remaining to charge in the constant current phase by a ratio of charging current measured in the pre-determined battery charging characteristics and an actual present charging current; and

calculating, by the apparatus, a total remaining charging time as a sum of the corrected remaining time in the constant current phase and a total duration of the constant voltage phase.

10. The method of claim 1, further comprising:

post filtering, by the apparatus, the calculated time remaining to charge by converting a duration of calculated time remaining to charge into an estimated charge completion instant by adding a present timestamp to the duration;

calculating, by the apparatus, an average of estimated charge completion instants; and

converting, by the apparatus, the average of the estimated charge completion instants into an estimated remaining charging duration by subtracting a current timestamp from the average of the estimated charge completion instants.

11. The method of claim 1, wherein a duration of the constant current phase is a pre-measured value of an estimated remaining charging time based on a battery stored charge estimate minus a pre-measured duration of the constant voltage phase, when the battery charging point is in the constant current phase.

12. The method of claim 11, wherein the duration of the constant current phase is corrected by a ratio of a pre-measured charging current and an actual present charging current;

and the time remaining to charge is a sum of the corrected duration of the constant current phase and a total duration of the constant voltage phase.

13. The method of claim 1, wherein a remaining charging time during the constant voltage phase is estimated as a mapping from charging current, using pre-measured data, when the battery charging point is in the constant voltage phase.

14. A non-transitory computer readable medium, comprising program instructions, which when executed by a computer processor, perform:

detecting an availability of a charger adapter;

determining whether a battery charging point is in a constant current phase or in a constant voltage phase, based on pre-determined battery charging characteristics, wherein the pre-determined battery charging characteristics comprise constant current phase charging characteristics and constant voltage phase charging characteristics;

calculating a time remaining to charge in the constant current phase based on the constant current phase charging characteristics, if the battery charging point is in the constant current phase; and

calculating a time remaining to charge in the constant voltage phase based on the constant voltage phase charging characteristics, if the battery charging point is in the constant voltage phase;

wherein the time remaining to charge in the constant current phase is based on stored charge characteristics in the constant current phase, when the battery charging point is in the constant current phase and wherein battery stored charge characteristics comprises a battery stored charge value based on monitored tracking of battery charging and discharging.

15. An apparatus, comprising:

at least one processor;

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the processor at least to;

detect an availability of a charger adapter;

determine whether a battery charging point is in a constant current phase or in a constant voltage phase, based on pre-determined battery charging characteristics, wherein the pre-determined battery charging characteristics comprise constant current phase charging characteristics and constant voltage phase charging characteristics;

calculate a time remaining to charge in the constant current phase based on the constant current phase charging characteristics, if the battery charging point is in the constant current phase; and

calculate a time remaining to charge in the constant voltage phase based on the constant voltage phase charging characteristics, if the battery charging point is in the constant voltage phase;

wherein the time remaining to charge in the constant current phase is based on stored charge characteristics in the constant current phase, when the battery charging point is in the constant current phase and wherein battery stored charge characteristics comprises a battery stored charge value based on monitored tracking of battery charging and discharging.

16. The apparatus of claim 15, wherein the battery stored charge characteristics comprise data that provides a remaining charging time estimate based on a battery stored charge estimate.