Load scheduling in multi-battery devices

Patent metadata

Field	Value
Publication number	US-10379587-B2
Application number	US-201715699317-A
Country	US
Kind code	B2
Filing date	Sep 8, 2017
Priority date	Apr 25, 2014
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

Various embodiments provide techniques and devices for scheduling power loads in devices having multiple batteries. Loads are characterized based on the power required to serve them. Loads are then assigned to batteries in response to the type of load and relative monitored characteristics of the batteries. The monitored battery characteristics can change over time. In some embodiments, stored profile information of the batteries can also be used in scheduling loads. In further embodiments, estimated workloads can also be used to schedule loads.

First claim

What is claimed is:

1. A method comprising:
monitoring at least one energy source characteristic of at least one of a plurality of batteries, the monitoring at least one energy source characteristic comprising calculating a quantity of energy expended from a first battery; and
selecting one of the plurality of batteries in response to the monitoring at least one energy source characteristic, the selecting one of the plurality of batteries comprising:
selecting according to a first selecting mode when the quantity of energy expended from the first battery is less than or equal to a switching threshold; and
selecting according to a second selecting mode when the quantity of energy expended from the first battery is greater than the switching threshold; and
scheduling a present load to the selected battery.

2. The method of claim 1 , further comprising:
calculating an estimated future workload; and
wherein the selecting according to a second selecting mode includes selecting the battery based in part of the estimated future workload.

3. The method of claim 2 , wherein the second selection mode comprises a separation mode, an investment mode, or a reservation mode.

4. The method of claim 3 , the investment mode comprising:
applying a greedy algorithm to choose a greedy-preferred battery from the plurality of batteries;
selecting the greedy-preferred battery when an estimated future workload predicts that a presently available position of the greedy-preferred battery will be filled with a low-power load regardless of the present selection; and
selecting a battery other than the greedy-preferred battery when a present load is high-power and the estimated future workload predicts that a presently available position of the greedy-preferred battery will be filled with a high-power load regardless of scheduling decisions.

5. The method of claim 3 , the reservation mode comprising:
identifying a first battery and a second battery, the first battery having an internal resistance higher than an internal resistance of the second battery and a first-battery maximal resistance lower than a second-battery maximal resistance of the second battery; and
selecting the second battery when the present load is low-power, the ratio of the second-battery maximal resistance to the first-battery maximal resistance exceeds a maximal resistance imbalance threshold, and an estimated future workload predicts a quantity of high-power loads sufficient to fill a remaining capacity of the first battery.

6. The method of claim 3 , the separation mode comprising:
identifying a first battery and a second battery, the first battery having an internal resistance higher than an internal resistance of the second battery;
selecting the first battery when the present load is low-power; and
selecting the second battery when the present load is high-power.

7. A method comprising:
monitoring at least one energy source characteristic of at least one of a plurality of batteries, the monitoring at least one energy source characteristic comprising:
monitoring at least one state of at least one of the plurality of batteries, the at least one state of at least one of the plurality of batteries comprising the value of at least one of a temperature, an age, or a number of discharge cycles completed of at least one of the plurality of batteries; and
accessing at least one stored characteristic of at least one of the plurality of batteries, the at least one stored characteristic of at least one of the plurality of finite energy sources comprising stored information of the internal resistance versus an energy output, stored information of the state of charge versus energy output, an initial internal resistance, a maximal resistance of at least one of the plurality of battery;
selecting one of the plurality of batteries in response to the monitoring at least one energy source characteristic; and
scheduling a present load to the selected battery.

8. The method of claim 7 , wherein the at least one stored characteristic is augmented or modified in response to a result of a previous application of the method.

9. A system comprising:
at least one computing device configured to be coupled to a first battery and a second battery configured to provide power to the at least one computing device;
a battery monitoring module configured to monitor at least one energy source characteristic of the first battery and the second battery and the age of the first battery and the second battery; and
a load scheduling module configured to:
select one of the first battery and the second battery in response to data provided to the load scheduling module by the battery monitoring module; the load scheduling module further configured to:
select according to a first selecting mode when the state of charge from the first battery or the second battery is less than or equal to a threshold; and
select according to a second selecting mode that is based in part on the age of the first battery and the second battery when the state of charge of the first battery and the state of charge from the second battery are both greater than the threshold; and
schedule a present load to at least one of the first battery and the second battery.

10. The method of claim 9 , wherein selecting according to a first selecting mode comprises selecting at least one of the first battery and the second battery according to a default policy.

11. The method of claim 9 , wherein selecting according to a second selecting mode comprises selecting the first battery when the age of the first battery is less than the age of the second battery.

12. The method of claim 9 , wherein selecting according to a second selecting mode comprises selecting the second battery when the age of the second battery is less than the age of the first battery.

13. The method of claim 9 , wherein determining an age of a first battery and a second battery includes determining a length of time from when the first battery and the second battery were manufactured.

14. The method of claim 9 , wherein determining an age of a first battery and a second battery includes determining a length of time from when the first battery and the second battery were first used to power a load.

15. The method of claim 9 , wherein determining an age of a first battery and a second battery includes determining a number of charge cycles that have been completed by the first battery and a number of charge cycles that have been completed by the first battery.

16. A system comprising:
at least one computing device configured to be coupled to a first battery and a second battery configured to provide power to the at least one computing device;
a battery monitoring module configured to monitor at least one energy source characteristic of the first battery and the second battery and the age of the first battery and the second battery; and
a load scheduling module configured to:
select one of the first battery and the second battery in response to data provided to the load scheduling module by the battery monitoring module; the load scheduling module further configured to:
select according to a first selecting mode when the state of charge from the first battery or the second battery is less than or equal to a threshold; and
select according to a second selecting mode that is based in part on the age of the first battery and the second battery when the state of charge of the first battery and the state of charge from the second battery are both greater than the threshold; and
schedule a present load to at least one of the first b

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Huang Bojun
• Meinershagen Julia L
• Moscibroda Thomas
• Hodges Stephen E
• Chandra Ranveer

Classifications

• H02J7/933

  the cycle being controlled or terminated in response to electric parameters · CPC title

• H02J7/865

  Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence) · CPC title

• H02J7/855

  with circuits adapted for supplying loads from the battery · CPC title

• H02J7/92 Primary

  with prioritisation of loads or sources · CPC title

• H02J7/34 Primary

  Parallel operation in networks using both storage and other DC sources, e.g. providing buffering (H02J7/14 takes precedence) · CPC title