Single Fuel Gauge for Multiple Energy Storage Devices

Patent metadata

Field	Value
Publication number	US-2017108906-A1
Application number	US-201514885858-A
Country	US
Kind code	A1
Filing date	Oct 16, 2015
Priority date	Oct 16, 2015
Publication date	Apr 20, 2017
Grant date	—

Abstract

A multiple energy storage device fuel gauge is described for a device having a power system with multiple heterogeneous energy storage devices. The fuel gauge keeps track of a present state of multiple heterogeneous energy storage devices simultaneously. The fuel gauge implements collective measurement of voltage and current of the multiple heterogeneous energy storage devices via shared circuitry to determine status information, such as state of charge (SOC) and internal resistance values. A controller of the fuel gauge uses various measurements and energy storage device-specific parameters to compute status values indicative of the state of each energy storage device. The status values are maintained by the fuel gauge and exposed to other system components to facilitate power management decisions. A communication bus is used to communicate between the fuel gauge and system components, and a software API may be exposed to facilitate access to various energy storage device specific information.

First claim

1 . A client computing device powered at least in part by energy storage devices, the client computing device comprising:
two or more heterogeneous energy storage devices included with the client computing device; a fuel gauge included in the client computing device and attached to the two or more energy storage devices, the fuel gauge including:
storage to maintain state of charge (SOC) estimation parameters for each of the energy storage devices attached to the fuel gauge, each of the SOC estimation parameters corresponding to characteristics of the respective energy storage devices;
a controller connected via shared circuitry to each of the energy storage devices attached to the fuel gauge, the controller operable to:
measure values indicative of a status of each of the energy storage devices attached to the fuel gauge; and
update status information corresponding to each of the energy storage devices attached to the fuel gauge based on the measured values and the SOC estimation parameters.

2 . The client computing device of claim 1 , wherein the controller of the fuel gauge includes shared voltage measuring circuitry configured to periodically measure the terminal voltage of the attached energy storage devices by time multiplexing.

3 . The client computing device of claim 1 , wherein the controller of the fuel gauge includes shared current measurement circuitry configured to periodically measure current flowing into or out of the attached energy storage devices by time multiplexing.

4 . The client computing device of claim 1 , wherein the controller is a single microcontroller.

5 . The client computing device of claim 1 , wherein the controller is a single sequential logic circuit.

6 . The client computing device of claim 1 , wherein the fuel gauge includes a communication interface operable to communicate the status information to a power management system of the client computing device.

7 . The client computing device of claim 6 , wherein the power management system is operable to output a user interface containing the status information of the power management system, the user interface configured to expose combined status for the two or more energy storage devices and individual statuses of the two or more energy storage devices.

8 . The client computing device of claim 1 , wherein the characteristics of the respective energy storage devices include energy storage device chemistries and physical features of the respective energy storage devices.

9 . The client computing device of claim 1 , wherein the status information comprises a SOC value, cycle count, estimated internal resistance, and estimated capacity of each of the energy storage devices attached to the fuel gauge.

10 . The client computing device of claim 1 , wherein the fuel gauge is configured to receive updates of SOC estimation parameters from an operating system of the client computing device.

11 . A method implemented by a computing device having two or more heterogeneous energy storage devices and a multiple energy storage device fuel gauge designed with shared measuring circuitry connected to the two or more heterogeneous energy storage devices, the method comprising:
receiving data measured via the shared measuring circuitry of the multiple energy storage device fuel gauge corresponding to at least voltage and current of the two or more heterogeneous energy storage devices, the received data corresponding to the voltage comprises voltage data measured via shared voltage measuring circuitry of the multiple energy storage device fuel gauge configured to periodically measure the terminal voltage of the attached heterogeneous energy storage devices by time multiplexing; computing one or more status values based on state of charge (SOC) estimation parameters for each of the heterogeneous energy storage devices and the received data corresponding to voltage and current of the two or more heterogeneous energy storage devices, the SOC estimation parameters corresponding to characteristics of the respective heterogeneous energy storage devices that are correlated to the received data to derive the one or more status values; and updating status information corresponding to each of the heterogeneous energy storage devices with the one or more status values as computed.

12 . (canceled)

13 . The method of claim 11 , wherein receiving the data comprises receiving current data measured via shared current measurement circuitry of the multiple energy storage device fuel gauge configured to periodically measure current flowing into or out of the attached heterogeneous energy storage devices by time multiplexing.

14 . The method of claim 11 , further comprising receiving data measured via the shared measuring circuitry of the multiple energy storage device fuel gauge corresponding to a number of executed charging events and discharging events of the respective heterogeneous energy storage devices.

15 . The method of claim 11 , wherein the status information comprises SOC values, internal resistance, and aging compensated capacity for each of the heterogeneous energy storage devices.

16 . The method of claim 11 , wherein the receiving, computing, and updating are performed by an operating system executed by the computing device in communication with a single microcontroller of the computing device that implements the multiple energy storage device fuel gauge.

17 . The method of claim 11 , further comprising exposing the status information for the multiple heterogeneous energy storage devices to other components of the computing device via an application programming interface (API) to facilitate power management actions based on the one or more status values.

18 . A method implemented by a power management controller of a client computing device that includes a multiple energy storage device fuel gauge, the method comprising:
storing state of charge (SOC) estimation parameters for two or more heterogeneous energy storage devices included with the client computing device, each of the SOC estimation parameters corresponding to characteristics of the respective heterogeneous energy storage devices; measuring via shared measuring circuitry of the multiple energy storage device fuel gauge at least voltage and current of the two or more heterogeneous energy storage devices; computing status values by correlating the SOC estimation parameters with the measured voltage and current of the two or more heterogeneous energy storage devices to derive status values including at least a SOC for each energy storage device and internal resistance for each energy storage device based on measured voltage and current values; updating status information corresponding to each of the heterogeneous energy storage devices to reflect the computed status values; and communicating the updated status information via a shared communication channel to an operating system of the client computing device to facilitate power management operations by the operating system.

19 . The method of claim 18 , wherein the characteristics of the respective heterogeneous energy storage devices include energy storage device chemistries and physical features of the respective heterogeneous energy storage devices.

20 . The method of claim 18 , further comprising receiving updates of SOC estimation parameters from the operating system of the client computing device and updating the SOC estimation parameters stored by the power management controller accordingly.

21

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Chandra Ranveer
• Badam Anirudh
• Dutra Jonathan Alan
• Meinershagen Julia L
• Hodges Stephen E
• Priyantha Nissanka Arachchige Bodhi

Classifications

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H02J7/50 Primary

  acting upon multiple batteries simultaneously or sequentially · CPC title

• G06F1/3203

  Power management, i.e. event-based initiation of a power-saving mode · CPC title

• G01R31/382

  Arrangements for monitoring battery or accumulator variables, e.g. SoC · CPC title

• G06F1/28 Primary

  Supervision thereof, e.g. detecting power-supply failure by out of limits supervision · CPC title