Estimating intrinsic resistance of button cell

Abstract

Techniques and apparatus for determining the intrinsic resistance and / or battery life of a button cell based on the recovery time of the cell voltage after a significant current draw event. Once the intrinsic resistance and / or battery life is known, a device powered by the button cell may take action to extend the service life of the cell. One example technique of operating a device powered by a battery generally includes performing an operation with a relatively high current draw to the battery compared to other operations of the device; determining a recovery time of a voltage of the battery after the operation; and estimating a location of the battery in a lifetime of the battery based on the recovery time.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Non-Provisional Application No. 18 / 446,348, filed on August 8, 2023, which claims the benefit of and priority to U.S. Provisional Application No. 63 / 370,886, filed on August 9, 2022, and U.S. Provisional Application No. 63 / 449,766, filed on March 3, 2023, both of which are expressly incorporated herein by reference in their entireties as if fully set forth below and for all applicable purposes. Technical Field

[0003] Certain aspects of the present disclosure relate generally to electronic circuits and, more particularly, to estimating the intrinsic resistance and / or battery life of a coin cell battery based on battery voltage recovery time. Background Art

[0004] A voltage regulator provides a constant direct current (DC) output voltage regardless of changes in load current or input voltage. Voltage regulators can be classified as linear regulators or switching regulators. Although linear regulators are small and compact, many applications can benefit from the improved efficiency of switching regulators. For example, linear regulators can be implemented by low dropout (LDO) regulators. Switching regulators can be implemented by switch mode power supplies (SMPS) such as buck converters, boost converters, buck-boost converters, or charge pumps.

[0005] A power management unit (PMU) is used to manage the power requirements of a host system and may include and / or control one or more voltage regulators (e.g., LDOs and / or SMPSs). A PMU may be used in battery-powered devices such as mobile phones, tablets, laptops, wearable devices, etc. to control the flow and direction of power in the device. The PMU may perform various functions for the device, such as DC to DC conversion (e.g., using a voltage regulator as described above), battery charging, power source selection, voltage scaling, power sequencing, etc. Summary of the invention

[0006] The systems, methods, and devices of the present disclosure each have several aspects, no single one of which is solely responsible for its desirable characteristics. Without limiting the scope of the present disclosure as expressed in the appended claims, some features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled "Detailed Description of the Invention," one will understand how the features of the present disclosure provide the advantages described herein.

[0007] Certain aspects of the present disclosure are generally directed to determining the inherent resistance and / or battery life of a coin cell battery based on the recovery time of the battery voltage after a significant current draw event. Once the inherent resistance and / or battery life are known, a device with a coin cell battery can take actions to extend the useful life of the battery.

[0008] Certain aspects of the present disclosure relate to a method of operating a device powered by a battery. The method generally includes: performing an operation with a relatively high current draw on a battery compared to other operations of the device; determining a recovery time of a voltage of the battery after the operation; and estimating a position of the battery in the life of the battery based on the recovery time.

[0009] Certain aspects of the present invention provide a device configured to be powered by a battery. The device generally includes a memory for storing executable instructions and at least one processor coupled to the memory and configured to execute the instructions so that the device: performs an operation under a relatively high current draw on a battery compared to other operations of the device; determines a recovery time of a voltage of the battery after the operation; and estimates a position of the battery in the life of the battery based on the recovery time.

[0010] Certain aspects of the present disclosure provide a non-transitory computer-readable medium including computer-executable instructions that, when executed by at least one processor of a battery-powered device, cause the device to perform a method. The method generally includes performing an operation with a relatively high current draw on a battery compared to other operations of the device; determining a recovery time of a voltage of the battery after the operation; and estimating a position of the battery in the life of the battery based on the recovery time.

[0011] Certain aspects of the present invention provide a device configured to be powered by a battery. The device generally includes: means for performing an operation with a relatively high current draw on the battery compared to other operations of the device; means for determining a recovery time of the voltage of the battery after the operation; and means for estimating the position of the battery in the life of the battery based on the recovery time.

[0012] To achieve the aforementioned and related purposes, one or more aspects include the features fully described below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain exemplary features of the one or more aspects. However, these features indicate only some of the various ways in which the principles of the various aspects can be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to be able to understand in detail the manner in which the above-mentioned features of the present disclosure are achieved, a more specific description briefly summarized above can be obtained by reference to various aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only certain typical aspects of the present disclosure and are therefore not to be considered as limiting the scope thereof, as the specification may admit to other equally effective aspects.

[0014] Figure 1 is a block diagram of an example device including a battery coupled to a power management unit (PMU) in accordance with certain aspects of the present disclosure.

[0015] Figure 2 is an example graph of intrinsic resistance versus used capacity for a coin cell battery according to certain aspects of the present disclosure.

[0016] Figure 3A and Figure 3B is an example graph of recovered battery voltage after an exemplary voltage drop in accordance with certain aspects of the present disclosure.

[0017] Figure 4 is a flow chart illustrating an example process for operating a battery-powered device in accordance with certain aspects of the present disclosure.

[0018] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation. DETAILED DESCRIPTION

[0019] Certain aspects of the present disclosure provide techniques and apparatus for determining the intrinsic resistance and / or battery life of a coin cell battery based on the recovery time of the battery voltage after a significant current draw event. Once the intrinsic resistance and / or battery life are known, a device powered by a coin cell battery can take actions to extend the useful life of the battery.

[0020] The various aspects of the present disclosure are described more fully below with reference to the accompanying drawings. However, the present disclosure can be embodied in many different forms, and should not be interpreted as being limited to any specific structure or function presented throughout the present disclosure. On the contrary, these aspects are provided so that the present disclosure will be thorough and complete, and the scope of the present disclosure will be fully conveyed to those skilled in the art. Based on the teachings of this article, it should be understood by those skilled in the art that the scope of the present disclosure is intended to cover any aspect of the disclosure disclosed herein, whether it is implemented independently or in combination with any other aspect of the present disclosure. For example, any number of aspects set forth herein can be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such a device or method that is practiced using other structures, functions, or structures and functions in addition to or different from the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein can be embodied by one or more elements of the claims.

[0021] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects.

[0022] As used herein, the term "connected with" in various tenses of the verb "connect" may mean that element A is directly connected to element B or that other elements may be connected between element A and element B (i.e., element A is indirectly connected to element B). In the context of electronic components, the term "connected with" may also be used herein to mean that wires, traces, or other conductive materials are used to electrically connect element A and element B (and any components electrically connected therebetween).

[0023] Example Device

[0024] It should be understood that various aspects of the present disclosure can be used for various applications. Although the present disclosure is not limited to this aspect, the circuits disclosed herein can be used in any of a variety of suitable devices, such as power supplies, battery charging circuits or power management circuits for communication systems, video codecs, audio equipment (such as music players and microphones), televisions, camera equipment, and / or test equipment (such as oscilloscopes). By way of example only, communication systems intended to be included within the scope of the present disclosure include cellular radiotelephone communication systems, satellite communication systems, two-way radio communication systems, one-way pagers, two-way pagers, personal communication systems (PCS), personal digital assistants (PDAs), Internet of Things (IoT) devices, etc.

[0025] Figure 1An example device 100 is illustrated in which aspects of the present disclosure may be implemented. Device 100 may be a battery-driven device such as a cellular phone, a PDA, a handheld device, a wireless device, a laptop, a tablet computer, a smart phone, a wearable device, an augmented reality device, or the like.

[0026] The device 100 may include a processor 104 that controls the operation of the device 100. The processor 104 may also be referred to as a central processing unit (CPU). A memory 106, which may include both read-only memory (ROM) and random access memory (RAM), provides instructions and data to the processor 104. A portion of the memory 106 may also include non-volatile random access memory (NVRAM). The processor 104 typically performs logical and arithmetic operations based on program instructions stored in the memory 106.

[0027] In some aspects, the device 100 may also include a housing 108, which may include a transmitter 110 and a receiver 112 to allow data to be sent and received between the device 100 and a remote location. For some aspects, the transmitter 110 and the receiver 112 may be combined into a transceiver 114. One or more antennas 116 may be attached to or otherwise mechanically coupled to the housing 108 and electrically coupled to the transceiver 114. The device 100 may also include (not shown) multiple transmitters, multiple receivers, and / or multiple transceivers.

[0028] The device 100 may also include a signal detector 118, which may be used to detect and quantify the signal level received by the transceiver 114. The signal detector 118 may detect signal parameters such as total energy, energy per subcarrier per symbol, and power spectral density and other signal parameters. The device 100 may also include a digital signal processor (DSP) 120 for processing signals.

[0029] The device 100 may also include a battery 122 for powering the various components of the device 100. For certain aspects, the battery 122 may be a button cell, such as a CR2032 battery, which is a round lithium battery that may be capable of delivering, for example, 220 milliamp hours (mAh). The device 100 may also include a power management unit (PMU) 123 for managing power from the battery to the various components of the device 100. At least a portion of the PMU 123 may be implemented in one or more power management integrated circuits (power management ICs or PMICs). The PMU 123 may perform various functions for the device 100, such as DC to DC conversion, battery charging, power source selection, voltage scaling, power sequencing, etc. For example, the PMU 123 may include a battery charging circuit (e.g., a master-slave battery charging circuit) for charging the battery 122. The PMU 123 may include one or more power supply circuits, which may include a switch mode power supply and / or a low dropout voltage regulator. The switched mode power supply may be implemented by any of a variety of suitable switched mode power supply circuit topologies, such as a buck converter, a boost converter, or a charge pump.

[0030] The various components of the device 100 may be coupled together via a bus system 126, which may include a power bus, a control signal bus, and / or a status signal bus in addition to a data bus. Additionally or alternatively, various combinations of components of the device 100 may be coupled together via one or more other suitable technologies.

[0031] Example coin cell battery intrinsic resistance determination

[0032] Micro-power Wi-Fi technology (eg, within the IEEE 802.11 family of standards, such as IEEE 802.11n) enables Wi-Fi devices to run on coin-cell batteries (eg, CR2032 batteries) and achieve useful battery life.

[0033] The coin cell battery intrinsic resistance (RINT) remains relatively constant until a point in the battery's lifecycle where RINT increases (e.g., increases exponentially), typically at about the half-life of the battery. As RINT increases, RINT can limit the battery's ability to power certain functions, such as high-power Wi-Fi transmissions or extensive Wi-Fi reception (e.g., involving over-the-air (OTA) updates), until a point where the battery eventually becomes unusable.

[0034] Figure 2 is a semi-logarithmic plot 200 of RINT 202 (in Ω on a logarithmic scale) versus used capacity 203 (in mAh on a linear scale) for an example CR2032 coin cell. Figure 2200 is represented by RINT data points 204 at different used capacities of RINT 202 and a RINT curve 206 fitted to the RINT data points 204. As illustrated by the graph 200, when the button cell is new (i.e., the used capacity is relatively low), the RINT 202 of the button cell tends to remain low and relatively constant. RINT 202 increases exponentially after about the midpoint in the life cycle of the battery (e.g., at a used capacity of about 100 mAh to 110 mAh). Figure 2 As illustrated, RINT 202 increases at a relatively linear rate until approximately 100 mAh of used capacity. After the used capacity reaches approximately 100 mAh, RINT 202 begins to increase exponentially. A rising inflection point 210 on the RINT curve 206 demarcates this change from a linear increase in RINT to an exponential increase.

[0035] Graph 200 also includes line 208 representing maximum RINT (eg, 40Ω to 50Ω) for a 30 mA load. After RINT 202 crosses line 208, the coin cell battery may not be able to provide sufficient current for certain operations of the device (eg, operations involving current draws in excess of 30 mA).

[0036] The time it takes for the coin cell battery voltage to recover after a significant current draw event (such as a Wi-Fi transmission) is proportional to the inherent resistance of the coin cell battery. Knowing the timeline of the coin cell battery voltage recovery provides an estimate of RINT, which can be used to limit or constrain the power used by certain functions. As RINT increases, the battery voltage recovery time generally increases as well.

[0037] Certain aspects of the present disclosure provide a mechanism for estimating the RINT and / or remaining life of a coin cell battery. pass Sure Battery voltage recovery time, RINT can be estimated using a variety of methods. For example, a moving average recovery time (e.g., with a sudden significant increase) can indicate that a RINT increase inflection point has been reached (e.g., inflection point 210 as illustrated in graph 200). Once a device powered by a button cell battery determines that the RINT increase inflection point of the button cell battery has been reached, the device can take one or more actions to extend the useful life of the button cell battery. For example, the device can extend the useful life of the button cell battery by reducing the transmit power, reducing the transmit burst length, using a physical layer (PHY) rate involving less power for transmission, reducing the idle period before entering a low power state, exiting a low power state less frequently, etc.

[0038] Figure 3A is an example graph 300 of battery voltage 301 over time illustrating a battery voltage recovery time 302 in accordance with certain aspects of the present disclosure.

[0039] According to certain aspects of the present disclosure, estimating RINT may involve monitoring the battery voltage during active transmission (TX) (intervals labeled “active TX”), as shown in curve 300. If the battery voltage 301 drops below a starting threshold 304 at time t1, measurement logic (e.g., in PMU 123 or processor 104 of device 100) may be enabled. For certain aspects, starting threshold 304 may be programmable.

[0040] Once the active TX is complete and the battery voltage has dropped to its local minimum level at time t2, the time taken for the battery voltage 301 to recover to the recovery threshold 306 at time t3 can be measured (during the interval labeled "Recovery Time" in the curve 300). This time is the battery voltage recovery time 302 (e.g., the time difference between time t3 and t2). For certain aspects, the recovery threshold 306 can be programmable. The recovery time measurement can be performed as a one-time measurement in some cases or within a time window in other cases. In the latter case, the worst case recovery time in the window can be reported as the measured recovery time.

[0041] Software running on the device may be provided with detailed information about the starting voltage level (e.g., the lowest battery voltage after crossing the starting threshold 304), the ending voltage level (e.g., the recovery threshold 306 or the maximum value of the highest battery voltage achieved during the recovery time 302), and / or the time it takes for the battery voltage 301 to recover (e.g., the recovery time 302). This would allow the software to adjust the power level and / or functionality of the device based on the estimated battery life (which is based on the inherent resistance estimated from the recovery time).

[0042] Figure 3B is an example graph 350 of battery voltage 351 over time illustrating recovery from a voltage drop in accordance with certain aspects of the present disclosure.

[0043] In the example curve 350, the battery voltage 351 does not drop below the start threshold 304 during active TX, and therefore, the measurement logic may not be enabled, thereby saving battery power and / or memory. That is, the time it takes for the battery voltage 351 to recover to the recovery threshold 306 may not be measured.

[0044] Example operation using coin cell battery intrinsic resistance determination

[0045] Figure 44 is a flow diagram illustrating example operations 400 for operating a device (e.g., device 100) powered by a battery (e.g., battery 122) in accordance with certain aspects of the present disclosure. Operations 400 may be performed by the device, and at least some of operations 400 may be controlled by a power management unit (PMU) (e.g., PMU 123) and / or one or more processors (e.g., processor 104) in the device.

[0046] Operations 400 may begin at block 402, where a device performs operations with a relatively high current draw on a battery compared to other operations of the device. For example, operations with a relatively high current draw may include sending a wireless signal from the device. As another example, operations with a relatively high current draw may include receiving a wireless signal at the device. In this case, the wireless signal received at the device may include an over-the-air (OTA) update for the device.

[0047] At block 404 , the device may determine a recovery time (eg, recovery time 302 ) of a voltage of a battery (eg, battery voltage 301 , 351 ) after performing the operation at block 402 .

[0048] At block 406, the device may estimate the position of the battery in the life of the battery based on the recovery time. In some aspects, estimating the position of the battery includes determining whether the battery is in the second half of the life of the battery. In this case, operation 400 may also include taking one or more actions to extend the usable life of the battery when it is determined that the battery is in the second half of the life of the battery.

[0049] According to certain aspects, determining the recovery time at block 404 includes performing a moving average of the recovery time. In this case, estimating the position of the battery in the life of the battery at block 406 may involve determining that a rising inflection point (e.g., inflection point 210) has occurred in the moving average of the recovery time.

[0050] According to certain aspects, operation 400 may also include estimating an intrinsic resistance of the battery (e.g., RINT 202) based on a recovery time of the voltage of the battery after operation. In this case, estimating the position of the battery in life may be based on the estimated intrinsic resistance. In some aspects, estimating the intrinsic resistance of the battery includes performing a moving average of the estimated intrinsic resistance. In this case, estimating the position of the battery in the life of the battery may include determining that a rising inflection point has occurred in the moving average of the estimated intrinsic resistance.

[0051] According to certain aspects, operation 400 may also include the device monitoring the voltage of the battery. In this case, operation under relatively high current draw conditions may cause the voltage of the battery to drop during operation. In certain aspects, determining the recovery time includes measuring the time taken from the end of the operation to the voltage of the battery reaching a first threshold voltage (e.g., recovery threshold 306). The first threshold voltage may be programmable. In certain aspects, operation 400 may also include the device determining whether the voltage of the battery drops below a second threshold voltage (e.g., starting threshold 304). In this case, determining the recovery time at block 404 and estimating the position of the battery at block 406 may be performed only if the voltage of the battery drops below the second threshold voltage. In certain aspects, at least one of the first threshold voltage or the second threshold voltage may be programmable.

[0052] According to certain aspects, operation 400 may also include the device taking one or more actions to extend the usable life of the battery based on the estimated position of the battery in the life of the battery. For example, taking the one or more actions may include at least one of the following: reducing the transmit power of the device, reducing the transmit burst length of the device, transmitting using a rate involving less power, reducing the idle period before entering a low power state of the device, exiting the low power state less frequently, or any combination thereof.

[0053] In some aspects, the battery can be a button cell battery. For example, the button cell battery can be a CR2032 battery.

[0054] In some aspects, the device may be an Internet of Things (IoT) device.

[0055] Sample Clauses

[0056] Specific implementation examples are described in the following numbered clauses:

[0057] Item 1: A method of operating a battery-powered device, the method comprising: performing an operation under relatively high current draw on the battery compared to other operations of the device; determining a recovery time for a voltage of the battery after the operation; and estimating a position of the battery in the life of the battery based on the recovery time.

[0058] Clause 2: The method of clause 1, wherein the estimating comprises determining whether the battery is in a second half of the life of the battery.

[0059] Clause 3: The method of clause 2, further comprising taking one or more actions to extend the useful life of the battery upon determining that the battery is in the second half of the life of the battery.

[0060] Clause 4: A method according to any one of clauses 1 to 3, the method further comprising estimating an intrinsic resistance of the battery based on the recovery time of the voltage of the battery after the operation, wherein estimating the position of the battery in the life is based on the estimated intrinsic resistance.

[0061] Clause 5: A method according to clause 4, wherein estimating the intrinsic resistance of the battery includes performing a moving average of the estimated intrinsic resistance, and wherein estimating the position of the battery in the life of the battery includes determining that a rising inflection point has occurred in the moving average of the estimated intrinsic resistance.

[0062] Clause 6: A method according to any one of clauses 1 to 5, wherein determining the recovery time includes performing a moving average of the recovery time, and wherein estimating the position of the battery in the life of the battery includes determining that a rising inflection point has occurred in the moving average of the recovery time.

[0063] Clause 7: A method according to any one of clauses 1 to 6, the method also includes monitoring the voltage of the battery, wherein the operation under the relatively high current draw condition causes the voltage of the battery to drop during the operation, and wherein determining the recovery time includes measuring the time taken from the end of the operation to the voltage of the battery reaching a first threshold voltage.

[0064] Clause 8: The method of clause 7, wherein the first threshold voltage is programmable.

[0065] Clause 9: The method according to clause 7 or 8, further comprising determining whether the voltage of the battery drops below a second threshold voltage, wherein determining the recovery time and estimating the position of the battery are performed only if the voltage of the battery drops below the second threshold voltage.

[0066] Clause 10: The method of Clause 9, wherein at least one of the first threshold voltage or the second threshold voltage is programmable.

[0067] Clause 11: The method of any of clauses 1 to 10, wherein the operation in the relatively high current draw condition comprises transmitting a wireless signal from the device.

[0068] Clause 12: The method of any of clauses 1 to 11, wherein the operation in the relatively high current draw scenario comprises receiving a wireless signal at the device.

[0069] Clause 13: The method of clause 12, wherein the wireless signal received at the device comprises an over-the-air (OTA) update for the device.

[0070] Clause 14: The method of any of clauses 1 to 13, further comprising taking one or more actions to extend a usable life of the battery based on the estimated position of the battery in the life of the battery.

[0071] Clause 15: A method according to clause 14, wherein taking the one or more actions includes at least one of the following: reducing the transmit power of the device; reducing the transmit burst length of the device; transmitting using a rate involving less power; reducing the idle period before entering a low power state of the device; exiting the low power state less frequently; or any combination thereof.

[0072] Clause 16: The method of any one of clauses 1 to 15, wherein the battery is a button cell.

[0073] Clause 17: The method of clause 16, wherein the button cell battery is a CR2032 battery.

[0074] Clause 18: A method as described in any one of clauses 1 to 17, wherein the device is an Internet of Things (IoT) device.

[0075] Clause 19: An apparatus comprising: a memory and at least one processor, the at least one processor coupled to the memory and configured to cause the apparatus to perform the method of any of clauses 1 to 18.

[0076] Clause 20: An apparatus comprising means for performing the method according to any one of clauses 1 to 18.

[0077] Clause 21: A non-transitory computer readable medium comprising computer executable instructions which, when executed by at least one processor of an apparatus, cause the apparatus to perform the method of any one of clauses 1 to 18.

[0078] Item 22: A device configured to be powered by a battery, the device comprising: a memory for storing executable instructions; and at least one processor coupled to the memory and configured to execute the instructions to: cause the device to perform an operation with a relatively high current draw on the battery compared to other operations of the device; determine a recovery time for a voltage of the battery after the operation; and estimate a position of the battery in the life of the battery based on the recovery time.

[0079] Clause 23: The device of clause 22, wherein to estimate the position of the battery, the at least one processor is configured to determine whether the battery is in a second half of the life of the battery.

[0080] Clause 24: The device of clause 23, wherein the at least one processor is further configured to, upon determining that the battery is in the second half of the life of the battery, cause the device to take one or more actions to extend the usable life of the battery.

[0081] Clause 25: A device according to any one of clauses 22 to 24, wherein the at least one processor is further configured to estimate the intrinsic resistance of the battery based on the recovery time of the voltage of the battery after the operation, and wherein the at least one processor is configured to estimate the position of the battery in the life of the battery based on the estimated intrinsic resistance.

[0082] Clause 26: A device according to clause 25, wherein in order to estimate the intrinsic resistance of the battery, the at least one processor is configured to perform a moving average of the estimated intrinsic resistance, and wherein in estimating the position of the battery in the life of the battery, the at least one processor is configured to determine that a rising inflection point has occurred in the moving average of the estimated intrinsic resistance.

[0083] Clause 27: A device according to any one of clauses 22 to 26, wherein in order to determine the recovery time, the at least one processor is configured to perform a moving average of the recovery time, and wherein in order to estimate the position of the battery in the life of the battery, the at least one processor is configured to determine that a rising inflection point has occurred in the moving average of the recovery time.

[0084] Clause 28: A device according to any one of clauses 22 to 27, wherein the at least one processor is further configured to monitor the voltage of the battery, wherein the operation in the relatively high current draw condition is configured to cause the voltage of the battery to drop during the operation, and wherein in order to determine the recovery time, the at least one processor is configured to determine the time it takes from the end of the operation to the voltage of the battery reaching a first threshold voltage.

[0085] Clause 29: The apparatus of clause 28, wherein the first threshold voltage is programmable.

[0086] Clause 30: A device according to clause 28 or 29, wherein in order to determine the recovery time, the at least one processor is further configured to determine whether the voltage of the battery drops below a second threshold voltage, and the at least one processor is configured to determine the recovery time and estimate the position of the battery only if the voltage of the battery drops below the second threshold voltage.

[0087] Clause 31: The apparatus of clause 30, wherein at least one of the first threshold voltage or the second threshold voltage is programmable.

[0088] Clause 32: A device as described in any of clauses 22 to 31, wherein the device is an Internet of Things (IoT) device.

[0089] Item 33: A non-transitory computer-readable medium comprising computer-executable instructions that, when executed by at least one processor of a battery-powered device, cause the device to perform a method comprising: performing an operation with a relatively high current draw on the battery compared to other operations of the device; determining a recovery time for a voltage of the battery after the operation; and estimating a position of the battery in the life of the battery based on the recovery time.

[0090] Clause 34: A device configured to be powered by a battery, the device comprising: means for performing an operation under conditions of relatively high current draw on the battery compared to other operations of the device; means for determining a recovery time for a voltage of the battery after the operation; and means for estimating a position of the battery in the life of the battery based on the recovery time.

[0091] Additional considerations

[0092] The various operations of the above methods may be performed by any suitable components capable of performing the corresponding functions. The components may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs), or processors. Typically, where there are operations illustrated in the accompanying drawings, those operations may have corresponding corresponding components plus functional components with similar numbers.

[0093] As used herein, the term "determine" encompasses a wide variety of actions. For example, "determine" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, a database, or another data structure), ascertaining, etc. In addition, "determine" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. In addition, "determine" may include resolving, selecting, choosing, establishing, etc.

[0094] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items (including single members). For example, "at least one of a, b, or c" is intended to cover: a, b, c, ab, ac, bc, and abc, as well as any combination with multiple of the same elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc or any other ordering of a, b, and c).

[0095] The methods disclosed herein include one or more steps or actions for implementing the described methods. The steps and / or actions of the methods may be interchangeable with each other without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0096] It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. A method of operating a battery powered device, the method comprising: performing operations at a relatively high current draw on the battery compared to other operations of the device; determining a recovery time of a voltage of the battery after the operation; as well as A position of the battery in the life of the battery is estimated based on the recovery time. 2 . The method of claim 1 , wherein the estimating comprises determining whether the battery is in a second half of the life of the battery.

3. The method of claim 2, further comprising taking one or more actions to extend the usable life of the battery when it is determined that the battery is in the second half of the life of the battery.

4. The method of claim 1 , further comprising estimating an intrinsic resistance of the battery based on the recovery time of the voltage of the battery after the operation, wherein estimating the position of the battery in the lifetime is based on the estimated intrinsic resistance.

5. A method according to claim 4, wherein estimating the inherent resistance of the battery includes performing a moving average of the estimated inherent resistance, and wherein estimating the position of the battery in the life of the battery includes determining that a rising inflection point has occurred in the moving average of the estimated inherent resistance.

6. The method of claim 1 , wherein determining the recovery time comprises performing a moving average of the recovery time, and wherein estimating the position of the battery in the life of the battery comprises determining that a rising inflection point has occurred in the moving average of the recovery time.

7. The method of claim 1 , further comprising monitoring the voltage of the battery, wherein the operation under the relatively high current draw condition causes the voltage of the battery to drop during the operation, and wherein determining the recovery time comprises measuring the time taken from the end of the operation to the voltage of the battery reaching a first threshold voltage. The method of claim 7 , wherein the first threshold voltage is programmable.

9. The method of claim 7, further comprising determining whether the voltage of the battery drops below a second threshold voltage, wherein determining the recovery time and estimating the position of the battery are performed only if the voltage of the battery drops below the second threshold voltage.

10. The method of claim 9, wherein at least one of the first threshold voltage or the second threshold voltage is programmable.

11. The method of claim 1 , wherein the operating in the relatively high current draw condition comprises transmitting a wireless signal from the device.

12. The method of claim 1, wherein the operating in the relatively high current draw condition comprises receiving a wireless signal at the device.

13. The method of claim 12, wherein the wireless signal received at the device comprises an over-the-air (OTA) update for the device.

14. The method of claim 1, further comprising taking one or more actions based on the estimated position of the battery in the life of the battery to extend the useful life of the battery.

15. The method of claim 14, wherein taking the one or more actions comprises at least one of: reducing the transmit power of the device; reducing the transmit burst length of the device; Transmitting using a rate involving less power; reducing an idle period before entering a low power state of the device; exiting the low power state less frequently; or Any combination of them.

16. The method of claim 1, wherein the battery is a button cell.

17. The method of claim 16, wherein the button cell is a CR2032 cell.

18. A device configured to be powered by a battery, the device comprising: a memory for storing executable instructions; and at least one processor coupled to the memory and configured to execute the instructions to: causing the device to operate at a relatively high current draw from the battery compared to other operations of the device; determining a recovery time of a voltage of the battery after the operation; as well as A position of the battery in the life of the battery is estimated based on the recovery time.

19. The device of claim 18, wherein to estimate the position of the battery, the at least one processor is configured to determine whether the battery is in a second half of the life of the battery.

20. The device of claim 19, wherein the at least one processor is further configured to, upon determining that the battery is in the second half of the life of the battery, cause the device to take one or more actions to extend the usable life of the battery.

21. The device of claim 18, wherein the at least one processor is further configured to estimate an intrinsic resistance of the battery based on the recovery time of the voltage of the battery after the operation, and wherein the at least one processor is configured to estimate the position of the battery in the life of the battery based on the estimated intrinsic resistance.

22. A device according to claim 21, wherein in order to estimate the intrinsic resistance of the battery, the at least one processor is configured to perform a moving average of the estimated intrinsic resistance, and wherein in order to estimate the position of the battery in the life of the battery, the at least one processor is configured to determine that a rising inflection point has occurred in the moving average of the estimated intrinsic resistance.

23. The apparatus of claim 18, wherein to determine the recovery time, the at least one processor is configured to perform a moving average of the recovery time, and wherein to estimate the position of the battery in the life of the battery, the at least one processor is configured to determine that a rising inflection point has occurred in the moving average of the recovery time.

24. The apparatus of claim 18, wherein the at least one processor is further configured to monitor the voltage of the battery, wherein the operation in the relatively high current draw condition is configured to cause the voltage of the battery to drop during the operation, and wherein to determine the recovery time, the at least one processor is configured to determine the time it takes from the end of the operation to the voltage of the battery to reach a first threshold voltage.

25. The apparatus of claim 24, wherein the first threshold voltage is programmable.

26. The device of claim 24, wherein, in order to determine the recovery time, the at least one processor is further configured to determine whether the voltage of the battery drops below a second threshold voltage, and the at least one processor is configured to determine the recovery time and estimate the position of the battery only if the voltage of the battery drops below the second threshold voltage.

27. The apparatus of claim 26, wherein at least one of the first threshold voltage or the second threshold voltage is programmable.

28. The device of claim 18, wherein the device is an Internet of Things (IoT) device.

29. A non-transitory computer-readable medium comprising computer-executable instructions that, when executed by at least one processor of a battery-powered device, cause the device to perform a method comprising: performing operations at a relatively high current draw on the battery compared to other operations of the device; determining a recovery time of a voltage of the battery after the operation; as well as A position of the battery in the life of the battery is estimated based on the recovery time.

30. A device configured to be powered by a battery, the device comprising: means for performing operation at a relatively high current draw from the battery compared to other operation of the device; means for determining a recovery time of the voltage of the battery after the operation; and Means for estimating a position of the battery in the life of the battery based on the recovery time.

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