Load allocation for multi-battery devices

• US 10,263,421 B2
• Filed: 07/14/2017
• Issued: 04/16/2019
• Est. Priority Date: 02/26/2015
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Huang, Bojun, Moscibroda, Thomas, Chandra, Ranveer, Hodges, Stephen E., Meinershagen, Julia L., Priyantha, Nissanka Arachchige Bodhi, Badam, Anirudh, Hu, Pan, Ferrese, Anthony John, Skiani, Evangelia
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Pham, Duc M
• Application Number:
  US15/650,666
• Publication Number:
  US 20170317493A1
• Time in Patent Office: 641 Days
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0025 Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/36 Arrangements using end-cell switching
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

This document describes techniques and apparatuses of load allocation for multi-battery devices. In some embodiments, these techniques and apparatuses determine an amount of load power that a multi-battery device consumes to operate. Respective efficiencies at which the device'"'"'s multiple batteries are capable of providing power are also determined. A respective portion of load power is then drawn from each of the batteries based on their respective efficiencies.

Claims

1. A computer-implemented method comprising:

drawing, from a first battery cell of a device, load power to support a workload of the device;

determining that an efficiency at which the first battery cell is capable of powering a future workload is not optimal; and

charging, via a second battery cell of the device, the first battery cell effective to improve the efficiency at which the first battery is capable of powering the future workload.

2. The computer-implemented method of claim 1, wherein the workload is allocated by a sequential algorithm configured to draw the load power from the first battery cell and the second battery cell sequentially.

3. The computer-implemented method of claim 1, wherein the workload is allocated by a least-resistance algorithm configured to allocate the load power based on instantaneous power level of a load and instantaneous respective internal resistances of the first battery cell and the second battery cell.

4. The computer-implemented method of claim 1, wherein the workload is allocated by a threshold algorithm configured to draw the load power from the first battery cell and the second battery cell based on thresholds for state of charge or internal resistance for the respective battery cells.

5. The computer-implemented method of claim 1, wherein the workload is a low-powered workload for a predicted sleep time or a standby time for the device.

6. The computer-implemented method of claim 1, wherein the future workload is a high-powered workload, and wherein the determining is based on a previous discharge of the first battery cell.

7. The computer-implemented method of claim 1, wherein the determining occurs responsive to an unexpected user interaction with the device.

8. The computer-implemented method of claim 1, wherein the charging the first battery cell increases the first battery cell'"'"'s state of charge and decreases the first battery cell'"'"'s internal resistance.

9. A computing device comprising:

multiple batteries configured to provide power to enable operation of the computing device;

switching circuitry configured to enable the power to be drawn from each of the multiple batteries;

sensing circuitry configured to measure load power consumed by the computing device to operate; and

a load manager configured to perform operations comprising;

drawing, from a first battery cell of the multiple battery cells, load power to support a workload of the computing device;

determining that an efficiency at which the first battery cell is capable of powering a future workload is not optimal; and

charging, via a second battery cell of the multiple battery cells, the first battery effective to improve the efficiency at which the first battery cell is capable of powering the future workload.

10. The computing device as described in claim 9, wherein the workload is a low-powered workload for a predicted sleep time or a standby time for the computing device.

11. The computing device as described in claim 9, wherein the future workload is a high-powered workload, and wherein the determining is based on a previous discharge of the first battery cell.

12. The computing device as described in claim 9, wherein the determining occurs responsive to an unexpected user interaction with the computing device.

13. The computing device as described in claim 9, wherein the charging the first battery cell increases the first battery cell'"'"'s state of charge and decreases the first battery cell'"'"'s internal resistance.

14. The computing device as described in claim 9, wherein the efficiency at which the first battery cell is capable of providing power is determined based on one or more of the first battery cell'"'"'s state-of-charge, internal resistance, age, cycle count, temperature, chemistry, circuit topology, or capacity.

15. A system comprising:

a first battery and a second battery configured to provide power to enable operation of the computing device;

switching circuitry configured to enable the power to be drawn from each of the first battery and the second battery;

sensing circuitry configured to measure load power consumed by the system to operate; and

a load allocator configured to perform operations comprising;

determining, via an algorithm and based on respective efficiencies of the first battery and the second battery, an allocation of load power being consumed by the system to the first battery and the second battery to maximize an efficiency at which the first battery and the second battery power the system;

drawing, from the first battery, load power to support a workload of the system;

determining, via the algorithm and based on the efficiency of the first battery, that an efficiency at which the first battery is capable of powering a future workload is not optimal; and

charging, via the second battery, the first battery effective to improve the efficiency at which the first battery is capable of powering the future workload.

16. The system as described in claim 15, wherein the algorithm includes one or a variable-weighted algorithm, a sequential algorithm, a least-resistance algorithm, or a threshold algorithm.

17. The system as described in claim 16, wherein:

the sequential algorithm is configured to allocate the load power such that the load power is drawn sequentially from the first battery and the second battery;

the least-resistance algorithm is configured to allocate the load power based on an instantaneous power level of the load and an instantaneous respective internal resistance of the first battery and the second battery;

or

the threshold algorithm is configured to allocate the load power based on a predefined threshold for a state-of-charge or internal resistance of the first battery and the second battery.

18. The system as described in claim 16, wherein the allocation of load power is determined based on a hybrid algorithm that includes use of the variable-weighted algorithm, the sequential algorithm, or the least-resistance algorithm based on the threshold algorithm.

19. The system as described in claim 15, wherein the workload is a low-powered workload for a predicted sleep time or a standby time for the system, and wherein the future workload is a high-powered workload.

20. The system as described in claim 15, wherein the charging the first battery increases the first battery'"'"'s state of charge and decreases the first battery'"'"'s internal resistance.