WO2023272423A1

WO2023272423A1 - Reserve battery capacity determinations

Info

Publication number: WO2023272423A1
Application number: PCT/CN2021/102669
Authority: WO
Inventors: Jen-Hao TAI; Chien Kun WANG; Xiao Kai MAO; Wen-Ching CHIOU
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2021-06-28
Filing date: 2021-06-28
Publication date: 2023-01-05

Abstract

In an example, an electronic device may include a battery pack. The battery pack may include a battery having a first cell and a second cell. Further, the battery pack may include a fuel gauge controller connected to the battery. The fuel gauge controller may monitor a parameter associated with the battery. In an example, the parameter may include a cell imbalance delta voltage between the first cell and the second cell, a charge cycle count, a total battery operating time, or any combination thereof. Further, the fuel gauge controller may determine, in real time, a percentage of battery capacity to be reserved based on the monitored parameter.

Description

RESERVE BATTERY CAPACITY DETERMINATIONS

BACKGROUND

Portable electronic devices are becoming increasingly popular. For example, the portable electronic devices may include notebooks, tablets, convertible devices, or the like. Such electronic devices may be powered by battery packs. The battery packs may include rechargeable batteries, such as Nickel batteries, Lithium batteries, and the like and maybe capable of providing power to the electronic devices, for instance, for several hours. Such rechargeable batteries may include a reserve capacity to facilitate a graceful shut down of an electronic device before the battery is no longer capable of powering the electronic device.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples are described in the following detailed description and in reference to the drawings, in which:

FIG. 1 is a block diagram of an example electronic device, including a fuel gauge controller to determine a percentage of a battery capacity to be reserved;

FIG. 2A is a block diagram of an example electronic device, including a processor to update a reserve capacity of a battery;

FIG. 2B is a block diagram of the example electronic device of FIG. 2A, depicting additional features;

FIG. 3 depicts an example matrix table of the electronic device of FIG. 2A, including mapping information to map reserve capacities with conditions of the battery; and

FIG. 4 is a block diagram of an example electronic device including a non-transitory machine-readable storage medium, storing instructions to determine a capacity of a battery to be reserved to perform an action.

DETAILED DESCRIPTION

Rechargeable batteries may be used as a source of power to electronic devices. A “battery capacity” or a “full charge capacity” may be a measure of a charge stored by a battery and is determined by a mass of active material contained in the battery. Further, a state of charge of the battery may refer to a level of charge relative to the battery capacity. In some examples, the state of charge of the battery may be monitored by a battery fuel gauge connected to the battery. The state of charge may be then displayed to a user so that the user can be made aware of a remaining battery life and can adjust the electronic device usage accordingly.

In some examples, the state of charge may be used by the electronic device to ensure that the electronic device can shut down in an orderly fashion before the battery is no longer capable of powering the electronic device. In this example, areserve capacity may be defined for the electronic device based on the state of charge. The reserve capacity may be referred as a critical/reserve battery level to initiate an action such as a sleep, hibernate, or shut down depending on a user-defined setting. When the battery reaches the reserve capacity, the action may be initiated to safeguard any abrupt shut down and data loss of the electronic device. In such examples, avalue for the reserve capacity may be entered by the user or manufacturer of the electronic device, or any other value calculated or entered by the battery fuel gauge.

However, the battery fuel gauge may include a level of inaccuracy when monitoring the state of charge of the battery. The level of inaccuracy may depend on various parameters (e.g., aging of internal battery components) of the battery and may reduce the utilizable capacity of the battery. Such inaccuracies may result in an abrupt shut down of the electronic device when the battery fuel gauge determines that the state of charge of the battery has reached the reserve capacity.

In some examples, the reserve capacity may be set to be higher than expected inaccuracies in the battery fuel gauge so that there is enough remaining state of charge in the battery to shut down the electronic device in the orderly fashion. However, in such examples, there can be some usable charge left in the battery after the electronic device has shut down. This remaining state of charge may not be available to the user of the electronic device and hence, in effect, reduces the total capacity of the battery which is available to the user.

Examples described herein may provide an electronic device including a battery pack. The battery pack may include a battery having a first cell and a second cell. Further, the battery pack may include a fuel gauge controller connected to the battery. The fuel gauge controller may monitor a parameter associated with the battery. The parameter may include a cell imbalance delta voltage between the first cell and the second cell, a charge cycle count, a total battery operating time, or any combination thereof. Further, the fuel gauge controller may determine a capacity of the battery to be reserved to perform an action (e.g., ashut-down operation) on the electronic device based on the monitored parameter. Furthermore, the fuel gauge controller may reserve the determined capacity of the battery to perform the action.

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present techniques. However, the example apparatuses, devices, and systems, may be practiced without these specific details. Reference in the specification to “an example” or similar language means that a particular feature, structure, or characteristic described may be included in at least that one example but may not be in other examples.

Turning now to the figures, FIG. 1 is a block diagram of an example electronic device 100, including a fuel gauge controller 110 to determine a percentage of a battery capacity to be reserved. Example electronic device 100 may include a notebook computer, a tablet computer, a smartphone, a workstation, or the like.

Electronic device 100 may include a battery pack 102. In an example, battery pack 102 may refer to a rechargeable battery pack with a built-in battery management system (BMS) , for use in electronic device 100. Further, battery pack 102 may include a battery 104. For example, battery 104 may refer to a hardware device that supplies power to electronic device 100, enabling electronic device 100 to operate without a power cord (i.e., without being connected to an external power supply) . Further, battery 104 may include multiple cells connected in serial and/or parallel configuration. In the example shown in FIG. 1, battery 104 may include a first cell 106 and a second cell 108.

Furthermore, battery pack 102 may include fuel gauge controller 110 connected to battery 104. In an example, fuel gauge controller 110 may include a chip that is electrically connected to first cell 106 and second cell 108. The chip can measure, detect, monitor, and/or identify parameters associated with first cell 106 and second cell 108.

During operation, fuel gauge controller 110 may monitor a parameter associated with battery 104. An example parameter may include a cell imbalance delta voltage between first cell 106 and second cell 108, a charge cycle count, a total battery operating time, or any combination thereof. In an example, fuel gauge controller 110 may utilize various sensors to measure information (e.g., voltage, current, charging behavior, or the like) indicative of the parameter. Further, fuel gauge controller 110 may determine the parameter associated with battery 104 using the measured information.

Such parameters may impact a capacity of battery 104. In an example, the charge cycle count may indicate a number of times battery 104 is charged, discharged, or a combination thereof. The charge cycle count may refer to a number of cycles that have elapsed, where a cycle is defined as a discharge and recharge of battery 104. In this example, the capacity of battery 104 may tend to decrease as the number of cycles increases (i.e., the capacity may tend to decrease each time battery 104 is used and recharged) .

Further, the total battery operating time may indicate a time during which electronic device 100 has been operated by battery 104. In an example, the total battery operating time may be determined by detecting a power off state of electronic device 100 and by sequentially adding up the operating time during which electronic device 100 has been operated by battery 104. In this example, the capacity of battery 104 may tend to decrease as the total battery operating time increases.

Furthermore, the cell imbalance delta voltage may include a difference in voltage between first cell 106 and second cell 108. The cell imbalance delta voltage may be caused by cells (e.g., first cell 106 and second cell 108) being charged to different state of charge levels. When battery 104 is overheated or overcharged, the cells may be prone to accelerated cell degradation and battery 104 may degrade the performance, which may result in the cell imbalance. The cell imbalance may vary voltage of each cell in battery pack 102 overtime and hence may decrease the capacity of battery 104.

For example, consider that battery 104 may include three 2200mAh cells (Qmax) . Further, consider that a first cell may be discharged by 100mAh (Q1) , asecond cell may be discharged by 100mAh (Q1) , and a third cell may be discharged by 200mAh (Q2) from a fully charged state. In this example, the state of charge of the first and second cells may be (Qmax-Q1) /Qmax=95.4%, but the state of charge of the third cell may be (Qmax-Q2) /Qmax=91%. Therefore, the third cell may be imbalanced by 4.4%. This in turn may result in a different open circuit voltage (i.e., the cell imbalance delta voltage) for the third cell compared to the first and second cells, because the open circuit voltage is in direct correlation with the state of charge.

Further during operation, fuel gauge controller 110 may determine, in real time, a percentage of the battery capacity to be reserved based on the monitored parameter. In this example, fuel gauge controller 110 may determine the percentage of the battery capacity to be reserved in first cell 106, second cell 108, or a combination thereof. Furthermore, fuel gauge controller 110 may reserve the determined percentage of the battery capacity in battery 104. In an example, the determined percentage of the battery capacity may be reserved for an application or an action prior to execution of the application or the action on electronic device 100. Such reserved battery capacity may ensure to complete the execution of the application or the action without a failure.

In an example, fuel gauge controller 110 may determine that the cell imbalance delta voltage is above a first threshold. Further, fuel gauge controller 110 may determine, in real time, the percentage of the battery capacity to be reserved in response to the determination that the cell imbalance delta voltage is above the first threshold.

In another example, fuel gauge controller 110 may determine that the charge cycle count is above a second threshold. Further, fuel gauge controller 110 may determine, in real time, the percentage of the battery capacity to be reserved in response to the determination that the cycle count is above the second threshold.

In yet another example, fuel gauge controller 110 may determine that the total battery operating time of battery 104 is above a third threshold. Further, fuel gauge controller 110 may determine, in real time, the percentage of the battery capacity to be reserved in response to the determination that the total battery operating time of battery 104 is above the third threshold.

FIG. 2A is a block diagram of an example electronic device 200, including a processor 212 to update a reserve capacity of a battery 206. As shown in FIG. 2A, electronic device 200 may include a storage device 202, battery 206, and processor 212 coupled to battery 206 and storage device 202. Example battery 206 may include a first cell 208 and a second cell 210. Processor 212 may be any type of central processing unit (CPU) , microprocessor, or processing logic that interprets and executes machine-readable instructions stored in a machine-readable storage medium. For example, processor 212 may be implemented as engines or modules including any combination of hardware and programming to implement the functionalities described herein.

Further, storage device 202 may store a matrix table 204. In an example, matrix table 204 may be generated through a design-of-experiments (DOE) approach. For example, matrix table 204 may be generated by considering information of various parameters (e.g., a cell imbalance delta voltage, a total battery operating time, and a charge cycle count) of battery 206 and the battery capacity to be reserved based on the parameters. An example matrix table 204 depicting mapping information between the parameters of battery 206 and the corresponding battery capacity to be reserved is shown in FIG. 3.

During operation, processor 212 may obtain information indicative of the cell imbalance delta voltage between first cell 208 and second cell 210, the total battery operating time, the charge cycle count, or a combination thereof of battery 206. In an example, processor 212 may obtain the information from a controller (e.g., a fuel gauge controller) and/or various sensors (e.g., a voltage sensor) associated with battery 206. Further, processor 212 may determine a percentage of the battery capacity to be reserved based on the obtained information using matrix table 204.

In an example, processor 212 may determine the cell imbalance delta voltage of battery 206, the total battery operating time of battery 206, the charge cycle count of battery 206, or any combination thereof from the obtained information. Further, processor 212 may determine a condition of battery 206 as a function of the cell imbalance delta voltage, the total battery operating time, the charge cycle count, or any combination thereof. In this example, processor 212 may determine the condition of battery 206 based on a determination that the cell imbalance delta voltage of battery 206 is greater than a first threshold, the total battery operating time of battery 206 is greater than a second threshold, the charge cycle count of battery 206 is greater than a third threshold, or any combination thereof. Furthermore, processor 212 may determine the percentage of the battery capacity to be reserved corresponding to the determined condition using matrix table 204. Furthermore, processor 212 may update a reserve capacity of battery 206 based on the determined percentage.

FIG. 2B is a block diagram of example electronic device 200, depicting additional features. For example, similarly named elements of FIG. 2B may be similar in structure and/or function to elements described with respect to FIG. 2A. As shown in FIG. 2B, electronic device 200 may include a display panel 252. Example display panel 252 may include a display screen (e.g., a user interface) on which information can be displayed to a user of electronic device 200. In an example, upon updating the reserve capacity of battery 206, processor 212 may output a signal indicative of the updated reserve capacity on the user interface of electronic device 200. Further, processor 212 may output an alert message on display panel 252 when a charge of battery 206 reaches the updated reserve capacity. Example alert message may include a critical message or a warning message indicating that a remaining battery capability is not enough to perform operations on electronic device 200.

FIG. 3 depicts an example matrix table 204 of electronic device 200 of FIG. 2A, including mapping information to map reserve capacities 304 (i.e., the battery capacities to be reserved) with conditions 302 of battery 206. For example, similarly named elements of FIG. 3 may be similar in structure and/or function to elements described with respect to FIGs. 2A and 2B. In the example shown in FIG. 3, conditions 302 of battery 206 may be determined as a function of information associated with various parameters. Matrix table 204 may facilitate in determining reserve capacity 304 of battery 206 corresponding to a determined condition 302. For example, matrix table 204 may be generated through a DOE approach, which is used to identify a cause (e.g., the parameters affecting the battery capacity) and effect (e.g., the battery capacity to be reserved based on the parameters) relationship.

In the example shown in FIG. 3, the parameters may include a charge cycle count 306, acell imbalance delta voltage 308, and a total battery operating time 310. Further, matrix table 204 may include reserve capacity 304 for different conditions 302 (e.g., condition 1 to condition 5) . In an example condition 1, when charge cycle count 306 is 50, cell imbalance delta voltage 308 is 50, and total battery operating time 310 is 2160 hours, then 1%of battery capacity may be reserved as reserve capacity 304 for electronic device 200. In an example condition 2, when charge cycle count 306 is 150, cell imbalance delta voltage 308 is 150, and total battery operating time 310 is 8640 hours, then 3%of battery capacity may be reserved as reserve capacity 304 for electronic device 200. Thus, matrix table 204 may facilitate in interpolating and extrapolating reserve capacity 304 for various possible conditions of the parameters (e.g., charge cycle count 306, cell imbalance delta voltage 308, and total battery operating time 310) associated with battery 206.

FIG. 4 is a block diagram of an example electronic device 400 including a non-transitory machine-readable storage medium 404, storing instructions to determine a capacity of a battery to perform an action. Electronic device 400 may include a processor 402 and machine-readable storage medium 404 communicatively coupled through a system bus. Processor 402 may be any type of central processing unit (CPU) , microprocessor, or processing logic that interprets and executes machine-readable instructions stored in machine-readable storage medium 404.

Machine-readable storage medium 404 may be a random-access memory (RAM) or another type of dynamic storage device that may store information and machine-readable instructions that may be executed by processor 402. For example, machine-readable storage medium 404 may be synchronous DRAM (SDRAM) , double data rate (DDR) ,

DRAM (RDRAM) ,

RAM, etc., or storage memory media such as a floppy disk, a hard disk, a CD-ROM, a DVD, a pen drive, and the like. In an example, machine-readable storage medium 404 may be a non-transitory machine-readable medium, where the term “non-transitory” does not encompass transitory propagating signals. In an example, machine-readable storage medium 404 may be remote but accessible to electronic device 400.

Machine-readable storage medium 404 may store instructions 406-410. In an example, instructions 406 may be executed by processor 402 to monitor a parameter associated with a battery. In an example, the parameter may include a cell imbalance delta voltage, a charge cycle count, a total battery operating time, or any combination thereof. Instructions 408 may be executed by processor 402 to determine a capacity of the battery to be reserved to perform an action to modify an operating state of electronic device 400 based on the monitored parameter. In an example, instructions to determine the capacity of the battery to be reserved can be implemented using a matrix table. In another example, instructions to determine the capacity of the battery to be reserved can also be implemented using machine learning.

Instructions 410 may be executed by processor 402 to reserve the determined capacity of the battery to perform the action. In an example, the action to modify the operating state of electronic device 400 may include an action to shut down electronic device 400. The action to shut down electronic device 400 may include a graceful shut down of electronic device 400. For example, after a certain amount of time running on the battery, components of electronic device 400 can be gracefully powered off in anticipation of the battery being depleted without losing data.

Further, the graceful shut down may be based on an estimated time for shutting down electronic device 400. In this example, instructions to determine the capacity of the battery to be reserved may include instructions to determine the capacity of the battery to be reserved based on the estimated time for shutting down electronic device 400 and the monitored parameter.

In an example, instructions to determine the capacity of the battery to be reserved may include instructions to:

- determine that the cell imbalance delta voltage is above a first threshold, and

- determine the capacity of the battery to be reserved in response to the determination that the cell imbalance delta voltage is above the first threshold. In an example, the cell imbalance delta voltage may include a difference in cell voltages of the battery.

In another example, instructions to determine the capacity of the battery to be reserved may include instructions to:

- determine that the charge cycle count is above a second threshold, and

- determine the capacity of the battery to be reserved in response to the determination that the cycle count is above the second threshold.

In yet another example, instructions to determine the capacity of the battery to be reserved may include instructions to:

- determine that the total battery operating time is above a third threshold, and

- determine the capacity of the battery to be reserved in response to the determination that the total battery operating time is above the third threshold.

The above-described examples are for the purpose of illustration. Although the above examples have been described in conjunction with example implementations thereof, numerous modifications may be possible without materially departing from the teachings of the subject matter described herein. Other substitutions, modifications, and changes may be made without departing from the spirit of the subject matter. Also, the features disclosed in this specification (including any accompanying claims, abstract, and drawings) , and/or any method or process so disclosed, may be combined in any combination, except combinations where some of such features are mutually exclusive.

The terms “include, ” “have, ” and variations thereof, as used herein, have the same meaning as the term “comprise” or appropriate variation thereof. Furthermore, the term “based on” , as used herein, means “based at least in part on. ” Thus, afeature that is described as based on some stimulus can be based on the stimulus or a combination of stimuli including the stimulus. In addition, the terms “first” and “second” are used to identify individual elements and may not meant to designate an order or number of those elements.

The present description has been shown and described with reference to the foregoing examples. It is understood, however, that other forms, details, and examples can be made without departing from the spirit and scope of the present subject matter that is defined in the following claims.

Claims

An electronic device comprising:

a battery pack comprising:

a battery including a first cell and a second cell; and

a fuel gauge controller connected to the battery, wherein the fuel gauge controller is to:

monitor a parameter associated with the battery, wherein the parameter comprises a cell imbalance delta voltage between the first cell and the second cell, a charge cycle count, a total battery operating time, or any combination thereof; and

determine, in real time, a percentage of battery capacity to be reserved based on the monitored parameter.
The electronic device of claim 1, wherein the fuel gauge controller is to:

reserve the determined percentage of the battery capacity in the battery.
The electronic device of claim 1, wherein the fuel gauge controller is to:

determine the percentage of the battery capacity to be reserved in the first cell, the second cell, or a combination thereof.
The electronic device of claim 1, wherein the fuel gauge controller is to:

determine that the cell imbalance delta voltage is above a first threshold, wherein the cell imbalance delta voltage comprises a difference in voltage between the first cell and the second cell; and

determine, in real time, the percentage of the battery capacity to be reserved in response to the determination that the cell imbalance delta voltage is above the first threshold.
The electronic device of claim 1, wherein the fuel gauge controller is to:

determine that the charge cycle count is above a second threshold, wherein the charge cycle count is to indicate a number of times the battery is charged, discharged, or a combination thereof; and

determine, in real time, the percentage of the battery capacity to be reserved in response to the determination that the cycle count is above the second threshold.
The electronic device of claim 1, wherein the fuel gauge controller is to:

determine that the total battery operating time is above a third threshold, wherein the total battery operating time is to indicate a time during which the electronic device has been operated by the battery; and

determine, in real time, the percentage of the battery capacity to be reserved in response to the determination that the total battery operating time is above the third threshold.
An electronic device comprising:

a storage device to store a matrix table;

a battery including a first cell and a second cell; and

a processor coupled to the battery and the storage device to:

obtain information indicative of a cell imbalance delta voltage between the first cell and the second cell, a total battery operating time, a charge cycle count, or a combination thereof of the battery;

determine a percentage of battery capacity to be reserved based on the obtained information using the matrix table; and

update a reserve capacity of the battery based on the determined percentage.
The electronic device of claim 7, wherein the processor is to:

determine the cell imbalance delta voltage of the battery, the total battery operating time of the battery, the charge cycle count of the battery, or any combination thereof from the obtained information;

determine a condition of the battery as a function of the cell imbalance delta voltage, the total battery operating time, the charge cycle count, or any combination thereof; and

determine the percentage of the battery capacity to be reserved corresponding to the determined condition using the matrix table.
The electronic device of claim 8, wherein the processor is to:

determine the condition of the battery based on a determination that the cell imbalance delta voltage of the battery is greater than a first threshold, the total battery operating time of the battery is greater than a second threshold, the charge cycle count of the battery is greater than a third threshold, or any combination thereof.
The electronic device of claim 7, wherein the processor is to:

output a signal indicative of the updated reserve capacity on a user interface of the electronic device.
The electronic device of claim 7, further comprising:

a display panel, wherein the processor is to output an alert message on the display panel when a charge of the battery reaches the updated reserve capacity.
The electronic device of claim 7, wherein the matrix table is generated through a design-of-experiments (DOE) approach.
A non-transitory machine-readable storage medium encoded with instructions that, when executed by a processor of an electronic device, cause the processor to:

monitor a parameter associated with a battery, wherein the parameter comprises a cell imbalance delta voltage, a charge cycle count, a total battery operating time, or any combination thereof;

determine a capacity of the battery to be reserved to perform an action to modify an operating state of the electronic device based on the monitored parameter; and

reserve the determined capacity of the battery to perform the action.
The non-transitory machine-readable storage medium of claim 13, wherein the action to modify the operating state of the electronic device comprises an action to shut down the electronic device.
The non-transitory machine-readable storage medium of claim 14, wherein the action to shut down the electronic device comprises a graceful shut down of the electronic device.
The non-transitory machine-readable storage medium of claim 15, wherein the graceful shut down is based on an estimated time for shutting down the electronic device.
The non-transitory machine-readable storage medium of claim 16, wherein instructions to determine the capacity of the battery to be reserved comprise instructions to:

determine the capacity of the battery to be reserved based on the estimated time for shutting down the electronic device and the monitored parameter.
The non-transitory machine-readable storage medium of claim 13, wherein instructions to determine the capacity of the battery to be reserved comprise instructions to:

determine that the cell imbalance delta voltage is above a first threshold, wherein the cell imbalance delta voltage comprises a difference in cell voltages of the battery; and

determine the capacity of the battery to be reserved in response to the determination that the cell imbalance delta voltage is above the first threshold.
The non-transitory machine-readable storage medium of claim 13, wherein instructions to determine the capacity of the battery to be reserved comprise instructions to:

determine that the charge cycle count is above a second threshold; and

determine the capacity of the battery to be reserved in response to the determination that the cycle count is above the second threshold.
The non-transitory machine-readable storage medium of claim 13, wherein instructions to determine the capacity of the battery to be reserved comprise instructions to:

determine that the total battery operating time is above a third threshold; and

determine the capacity of the battery to be reserved in response to the determination that the total battery operating time is above the third threshold.