Heterogeneous Battery Cell Switching

Patent metadata

Field	Value
Publication number	US-2016248125-A1
Application number	US-201514626518-A
Country	US
Kind code	A1
Filing date	Feb 19, 2015
Priority date	Feb 19, 2015
Publication date	Aug 25, 2016
Grant date	—

Abstract

Heterogeneous battery cell switching techniques are described for a device having a battery system with heterogeneous battery cells. A control system is provided that is configured to implement a policy for switching a load for the device between the heterogeneous battery cells. The switching may involve selecting between multiple different modes supported by the device based on an assessment of an operational context for the device. Modes available for a heterogeneous battery cell system may include but are not limited to different modes to connect one of the multiple heterogeneous battery cell at a time to service the load, rapidly switch among the multiple heterogeneous battery cells to service the load by drawing a percentage of the overall load from each cell, and/or draw a set amount of current from each of the multiple heterogeneous battery cells to service the load.

First claim

What is claimed is:

1 . A method implemented by a computing device comprising:
analyzing an operational context for a computing device having a battery system with heterogeneous battery cells; selecting a switching mode to service a load of the computing device from among multiple switching modes supported by the battery system, the switching mode selected to match the operational context; and communicating control signals to direct switching hardware of the battery system to switch between the heterogeneous battery cells to service the load using the switching mode that is selected.

2 . The method of claim 1 , wherein the heterogeneous battery cells include at least two cells having different characteristics including differences in at least one of size, capacity, battery technology, chemistry, shape or state of charge (SOC).

3 . The method of claim 1 , wherein the multiple switching modes include different modes operable to:
connect one of the heterogeneous battery cells at a time to service the load; rapidly switch between the heterogeneous battery cells to service the load by drawing a percentage of the load from each heterogeneous battery cell; and simultaneously draw a set amount of current from each of the heterogeneous battery cells to service the load.

4 . The method of claim 1 , wherein analyzing the operational context includes tracking battery states, current battery workload, predicted future workload, thermal conditions, indications of user presence, and power availability.

5 . The method of claim 1 , wherein analyzing the operational context includes obtaining battery cell data communicated from a battery controller to facilitate power management operations and recognizing the operational context based at least in part upon the battery cell data.

6 . The method of claim 1 , wherein different modes of the multiple switching modes are mapped to different operational contexts.

7 . The method of claim 1 , wherein the control signals are configured to cause the switching hardware to selectively activate and deactivate cells of the heterogeneous battery cells as specified by the switching mode that is selected.

8 . The method of claim 1 , wherein communicating the control signals comprises communicating messages to direct operation of a power management integrated circuit of the battery system to set registers of the power management integrated circuit to cause implementation of the switching mode that is selected.

9 . A battery system for a computing device comprising:
heterogeneous battery cells; and a battery controller including:
switching hardware operable to selectively draw power from the heterogeneous battery cells; and
control logic to control the switching hardware in accordance with a switching policy established for the computing device to switch between the heterogeneous battery cells.

10 . A battery system as recited in claim 9 , wherein the battery controller is configured to support multiple different switching modes.

11 . A battery system as recited in claim 9 , wherein the switching hardware includes a solid state switch that is positionable to select between the heterogeneous battery cells and a capacitor buffer associated with each of the heterogeneous battery cells to smooth current produced when switching between the heterogeneous battery cells.

12 . A battery system as recited in claim 9 , wherein the switching hardware is configured to rapidly switch among the heterogeneous battery cells to service a current load for the computing device by drawing a portion of the load from each heterogeneous battery cell.

13 . A battery system as recited in claim 12 , wherein the switching hardware is further configured to connect one of the heterogeneous battery cells at a time to service the current load.

14 . A battery system as recited in claim 9 , wherein control of the switching hardware in accordance with a switching policy includes:
tracking performance parameters for the heterogeneous battery cells of the battery system; based on the tracking, communicating data sufficient to facilitate selection of the switching policy to use for servicing a device load during a designated time period; responsive to communication of the data, obtain an indication of the switching policy that is selected for the designated time period; and during the designated time period, apply the switching policy that is selected to control operation of the switching hardware to service the device load by switching between the heterogeneous battery cells.

15 . A battery system as recited in claim 9 , wherein the battery controller is adapted to included registers configured to hold various parameters used by the control logic to control operation of switching hardware including registers indicative of at least a selected switching policy and battery specific constraints designated for the heterogeneous battery cells.

16 . A computing device comprising:
a battery system having heterogeneous battery cells; and a control system configured to implement a policy for switching a load for the device between the heterogeneous battery cells using multiple switching modes including different modes operable to:
connect one of the heterogeneous battery cells at a time to service the load;
rapidly switch among the heterogeneous battery cells to service the load by drawing a percentage of the load from each heterogeneous battery cell; and
simultaneously draw a set amount of current from each of the heterogeneous battery cells to service the load.

17 . A computing device as recited in claim 16 , wherein the battery system further includes a battery controller having switching hardware and control logic operable to selectively switch between use of different cells of the heterogeneous battery cells at different times.

18 . A computing device as recited in claim 17 , wherein the control system includes a power manager module of an operating system of the computing device configured to direct operation of the switching hardware to set the battery system into the multiple switching modes.

19 . A computing device as recited in claim 18 , wherein the power manager module is further configured to:
obtain battery cell data communicated from the battery controller; recognize an operational context for the computing device based at least in part upon the battery cell data; select a mode of the multiple switching modes that matches the operational context; and communicate control signals to the battery controller to cause a switch by the switching hardware to operate the battery system using the mode that is selected.

20 . A computing device as recited in claim 19 , wherein the control signals are configured to cause a switch by setting values of registers implemented by the battery controller to indicate the mode that is selected and battery specific switching constraints designated for cells of the heterogeneous battery cells.

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Huang Bojun
• Hu Pan
• Ferrese Anthony John
• Skiani Evangelia
• Priyantha Nissanka Arachchige Bodhi
• Chandra Ranveer
• Badam Anirudh
• Hodges Stephen E
• Meinershagen Julia L
• Moscibroda Thomas
• Dutra Jon

Classifications

• H02J7/933

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

• H02J7/855 Primary

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

• H01M2010/4278

  Systems for data transfer from batteries, e.g. transfer of battery parameters to a controller, data transferred between battery controller and main controller · CPC title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H01M10/4207

  for several batteries or cells simultaneously or sequentially · CPC title