Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
  • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
  • G01R31/3644—Constructional arrangements
  • G01R31/3646—Constructional arrangements for indicating electrical conditions or variables, e.g. visual or audible indicators
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
  • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
  • G01R31/382—Arrangements for monitoring battery or accumulator variables, e.g. SoC
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
  • H01M10/425—Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing
  • H01M10/4257—Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
  • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
  • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
  • H01M10/488—Cells or batteries combined with indicating means for external visualization of the condition, e.g. by change of colour or of light density
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/50—Methods or arrangements for servicing or maintenance, e.g. for maintaining operating temperature
  • H01M6/5044—Cells or batteries structurally combined with cell condition indicating means
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/50—Methods or arrangements for servicing or maintenance, e.g. for maintaining operating temperature
  • H01M6/5044—Cells or batteries structurally combined with cell condition indicating means
  • H01M6/505—Cells combined with indicating means for external visualization of the condition, e.g. by change of colour or of light intensity
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/50—Methods or arrangements for servicing or maintenance, e.g. for maintaining operating temperature
  • H01M6/5044—Cells or batteries structurally combined with cell condition indicating means
  • H01M6/5061—Cells combined with sound indicating means
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries
  • H02J7/80—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries including monitoring or indicating arrangements
  • H02J7/82—Control of state of charge [SOC]
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries
  • H02J7/80—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries including monitoring or indicating arrangements
  • H02J7/82—Control of state of charge [SOC]
  • H02J7/825—Detection of fully charged condition
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries
  • H02J7/80—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries including monitoring or indicating arrangements
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries
  • H02J7/80—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries including monitoring or indicating arrangements
  • H02J7/84—Control of state of health [SOH]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the present invention relates to a capacity indicator for use in a battery.
• This technology may find particular application in rechargeable batteries or intelligent batteries, however this should not be seen as limiting on the scope of the technology.
• Batteries are needed and used by almost every household worldwide. It is believed that a total of 350 AA and 150 AAA are batteries are purchased every second of every day.
• the main types of household batteries available are alkaline, lithium, nickel-metal hydride (NiMH) and nickel-cadmium (NiCD) batteries.
• NiMH nickel-metal hydride
• NiCD nickel-cadmium
• Batteries are provided with a rated capacity, typically expressed in milliamp hours (mAh) or amp hours (Ah). This rated capacity can be used to estimate the run time of a device if the current draw of the device is known. However, this requires a degree of knowledge on behalf of the battery user. Furthermore, in devices which require multiple batteries, the user must be able to determine whether the batteries are connected in series or parallel in order to make an accurate estimate of remaining run time.
• Using rated capacity to determine the run-time of a device also only works when the batteries are new and haven't already been used. Even unused batteries self-discharge over time, meaning that the available energy may be much lower than the rated capacity of the battery.
• Battery testers are available for determining the capacity remaining in a battery. These devices are typically much larger than the battery being tested, and have LEDs or a display for indicating the battery capacity to the user. These battery testers typically operate by monitoring the terminal voltage of the battery and in some cases applying a load to the battery to see how the terminal voltage varies. This approach can be used to provide an estimate of the capacity of the battery.
• thermochromic liquid crystal strip which changes colour as it is heated. This thermochromic strip is activated when specific regions of the battery are pushed. Applying pressure to these regions connects a resistive element between the battery terminals which heats up, in turn heating the thermochromic strip. The result is a colour change in the thermochromic strip which can be used to provide a rough indication of the remaining capacity of the battery.
• the advantage of the Duracell approach is that there is no longer a need to use a bulky external battery tester, as each battery has its own tester built-in.
• this approach has a number of limitations. Firstly, as the capacity indication is dependent on temperature, the resulting indication could vary depending on the temperature of the surrounding environment.
• this approach relies on the heating of the thermochromic strip, there is a short delay as the strip heats up. This heating of the thermochromic strip also places a load on the battery which causes the battery to discharge as it is being tested.
• batteries that employ this technology typically have activation regions which require a forceful press to activate, thereby reducing the likelihood that the testing circuit would be inadvertently activated which would drain the battery when not required.
• a further downside of requiring a forceful press on the activation regions means that the testing circuit could be difficult to activate by children, the frail or elderly.
• a battery capacity indicator According to a first aspect of the technology, there is provided a battery capacity indicator.
• a battery comprising a battery capacity indicator.
• a battery comprising electronics which are configured to communicate one or more parameters of the battery to a user.
• a battery capacity indicator comprising: an activation circuit; a capacity determination circuit; an indicator; and wherein the activation circuit is configured to activate the capacity determination circuit upon receiving an external input, wherein the capacity determination circuit is configured to determine a capacity of a power source of a battery, and to relay a signal representative of said capacity to the indicator, wherein the indicator is configured to indicate the capacity to a user, and wherein the capacity determination circuit is configured to be housed in a battery.
• a battery comprising: a power source; a housing comprising a positive terminal and a negative terminal; and at least one electronic circuit operatively connected between the power source and the positive and/or negative terminals of the battery, wherein the electronic circuit is configured, upon receiving an external input, to communicate at least one parameter of the battery externally to the housing.
• a battery capacity indicator comprising: an activation circuit; a capacity determination circuit; and an indicator; wherein the activation circuit is configured to activate the capacity determination circuit upon receiving a sequence of external inputs, wherein the capacity determination circuit is configured to determine capacity information of a power source of a battery, and to relay a signal representative of said capacity to the indicator, wherein the indicator is configured to indicate the capacity information to a user, and wherein the capacity determination circuit is configured to be housed in a battery.
• a battery comprising: a housing containing: a power source; and a capacity determination circuit; an activation circuit; and an indicator; wherein the activation circuit is configured to activate the capacity determination circuit upon receiving a sequence of external inputs, wherein the capacity determination circuit is configured to determine capacity information of the power source, and to relay a signal representative of said capacity to the indicator, wherein the indicator is configured to indicate the capacity information to a user.
• the at least one electronic circuit comprises the battery capacity indicator of the previous aspect of the technology, wherein the at least one parameter of the battery comprises the capacity of the power source.
• the battery may be a rechargeable battery.
• the power source may be a rechargeable power source.
• the battery may include a lithium- or nickel-based chemistry such as Li-ion, Li-po, NiMH or NiCD.
• the power source may include one or more lithium ion cells.
• the housing may have an AA or AAA form factor, however this should not be seen as limiting on the technology.
• the activation circuit may be configured to switch the electronic circuit/capacity determination circuit between a low-power state or off state and an active state.
• the activation circuit may be configured to provide an interrupt to a processor, or vary one or more power rails within the electronic circuit/capacity determination circuit.
• the current draw of the electronic circuit/capacity determination circuit may be less than 10 mA.
• the activation circuit may comprise an input means for receiving the external input.
• the input means may comprise a sensor such as an accelerometer, microphone, light sensor, pressure sensor or gyroscope, or a combination of sensors.
• the input means may be touch-based, for example a mechanical, capacitive, inductive, or resistive touch interface or button.
• the activation circuit may require a plurality of external inputs prior to activation.
• the indicator may be a visual indicator such as a light emitting diode (LED).
• the indicator may be an audible indicator or tactile indicator such as a buzzer, speaker or vibration motor.
• the indicator may be configured to indicate the capacity through a plurality of indication modes.
• the indicator may be located inside the housing.
• the indicator may be located externally to the housing, for example embedded in or positioned under a label which is external to at least a portion of the housing.
• the housing may comprise a translucent or transparent region.
• the transparent or translucent region may be configured such that the light from the visual indicator is visible outside of the battery housing.
• the label may also include a transparent or translucent region to allow the light from the visual indicator to be more readily visible.
• the electronic circuit/capacity determination circuit may comprise a processor.
• the electronic circuit/capacity determination circuit may comprise discrete electronics.
• the electronic circuit/capacity determination circuit may be configured to determine the capacity of the battery by one or more of the following methods:
• Calculating the internal resistance of the power source for example by measuring the voltage of the power source at one or more load currents; Estimating the capacity of the battery based on time, i.e. approximating the self-discharge of the battery; and
• the at least one parameter / capacity may be one or more of the following:
• the remaining capacity of the battery (for example, relative or absolute remaining capacity);
• the voltage of the power source for example the instantaneous, average, or historic voltage(s) such as maximum or minimum values observed;
• the current flowing into or out of the power source for example the instantaneous, average, or historic current(s) such as maximum or minimum values observed;
• the temperature of the power source for example the instantaneous, average, or historic temperature(s) such as maximum or minimum values observed;
• An indication of the state of health of the battery For example, in a rechargeable battery the electronics may provide an indication of how the maximum capacity of the battery has degraded from the rated capacity over time / charge cycles; and Historic data about the battery, for example the age of the battery, the number of charge/discharge cycles.
• Figure 1 shows a simplified diagram of a battery according to an embodiment of the present technology
• Figure 2 shows a block diagram of electronic components according to an embodiment of the present technology
• Figure 3 shows a block diagram of an exemplary capacity determination circuit which utilises a processor for the capacity measurement according to an embodiment of the present technology
• Figure 4 shows a simplified schematic of circuit according to an embodiment of the technology in which the capacity measurement is done using discrete electronic components
• Figure 5 shows a flow-diagram which illustrates an exemplary embodiment of how the capacity determination circuit may be kept in a low-power state
• Figure 6 shows circuit diagrams of exemplary electronic circuits comprised as part of a battery capacity indicator according to an embodiment of the present technology.
• a preferred embodiment of the present technology relates to a battery capacity indicator.
• the components of this embodiment at a high-level are first discussed with reference to Figure 1 below.
• FIG. 1 shows a simplified view of a battery 100 according to an embodiment of the present technology.
• the battery 100 is depicted as an AA battery as will be known to those skilled in the art. Flowever, this should not be seen as limiting on the technology, and other battery sizes may be used without departing from the scope of the technology.
• the battery 100 may have an AA, AAA, C, D, 9V, coin cell, button cell, or any other form factor known to those in the art, including for example mobile phone, drone, and vehicle battery forms.
• the battery 100 comprises a power source 102 which may comprise one or more primary (non- rechargable) or secondary (rechargeable) cells.
• the power source 102 is operatively connected to the positive 104 and negative terminals 106 of the battery 100, in order to provide the output voltage of the battery.
• the positive terminal 104 and negative terminal 106 are comprised as part of a housing 108.
• the power source 102 is housed inside the housing 108.
• a further aspect of the present technology is the inclusion of electronics 110 within the housing 108 of the battery 100.
• Inclusion of electronics 110 within the battery 100 may provide a number of advantages including the ability to:
• the electronics 110 are shown as being located entirely within the housing 108 of the battery 100, one or more components of the electronics 110 may instead or additionally be located within a separate part of the battery 100 such as the terminals 104, 106 or embedded in or otherwise positioned under the label 112.
• the label 112 is external to at least a portion of the housing 108, for example in various embodiments it may surround or be adhered to the outer surface of the housing 108.
• the Electronic components 110 may comprise a battery capacity indicator configured to provide an indication of a battery 100 within which it is housed.
• the electronic components 110 may include one or more of the following:
• a capacity determination circuit 200
• An activation circuit 202 An activation circuit 202
• An indicator 204 An indicator 204; and Input/output electronics 206.
• Each of these components may be operatively connected to the internal power source 102 and/or the terminals 104, 106 of the battery 100. The function of each of these components is discussed below.
• the capacity determination circuit 200 is configured to determine a capacity of the power source 102 of the battery 100. This information is relayed to an indicator 204 through a signal representative of the determined capacity of the power source 102 as will be discussed in further detail below.
• determining or the “determined” capacity should be understood to include both precise measurements of the capacity of the power source (or a parameter indicative of the capacity of the power source) as well as approximations or estimates of the capacity of the power source.
• the capacity determination circuit 200 may be configured to determine the capacity of the battery 100 in a number of different ways. For example, the capacity determination circuit 200 may determine the capacity of the battery 100 using one or more of the following methods:
• the capacity determination circuit 200 may measure the voltage of the power source 102 under a substantially zero load condition, then apply a known load such as a 50mA load and measure the voltage again to determine how much voltage is dropped across the internal resistance of the battery 100;
• the capacity determination circuit 200 may be configured to determine the capacity of the battery 100 using one or more of the above methods. For example, in cost-sensitive applications, it may be adequate to simply provide capacity estimation based on power source 102 voltage measurements alone. In contrast, in applications requiring precise measurement, capacity determination may include a combination of voltage, measurement, coulomb counting, and internal battery resistance calculations.
• the capacity determination circuit 200 may not need to be able to provide an absolute determination of capacity, and in some applications, a relative measure may be adequate, such as a percentage indication of the total rated capacity.
• a measured voltage of 4.2V may correlate to a capacity of approximately 100%
• 3.9V may correlate to a capacity of approximately 75% charge
• 3.75V may correlate to a capacity of approximately 50%
• 3.7V may correlate to a capacity of approximately 25%
• 3V may correlate to a capacity of approximately 0%.
• the capacity determination circuit 200 may be configured to alternatively and/or additionally determine one or more parameters of the battery 100 that may be considered to be indirectly representative of battery capacity, or otherwise, such as:
• the remaining capacity of the battery 100 (for example, relative or absolute remaining capacity);
• the rated capacity of the battery 100 The voltage of the power source 102, for example the instantaneous, average, or historic voltage(s) such as maximum or minimum values observed.
• the current flowing into or out of the power source 102 for example the instantaneous, average, or historic current(s) such as maximum or minimum values observed.
• the temperature of the power source 102 for example the instantaneous, average, or historic temperature(s) such as maximum or minimum values observed.
• An indication of the state of health of the battery 100 For example, in a rechargeable battery the electronics 110 may provide an indication of how the maximum capacity of the battery has degraded from the rated capacity over time / charge cycles; and Historic data about the battery 100, for example the age of the battery, the number of charge/discharge cycles.
• the capacity determination circuit 200 includes a processor 300 as shown in Figure 3.
• the processor 300 comprises one or more electrical connections 302 to the power source 102.
• the processor 300 may be configured to measure the voltage of one or more cells of the power source 102, by operatively connecting (either directly or via intermediate electronics 110 such as a voltage divider) these cells to an analogue input on the processor 300.
• the processor 300 may then be configured to provide an analogue to digital conversion of the voltage for the purposes of determining the capacity of the battery 100.
• the capacity determination circuit 200 may comprise one or more current detecting elements in series with the power source 102.
• these current detecting elements may be resistors such as current sense resistors 304.
• Current sense resistors 304 typically have a resistance in the order of milli-ohms in order to not adversely affect the performance of the battery 100. By measuring the differential voltages across the current sense resistor 304, it may be possible to determine the amount of current flowing in the circuit. It will be appreciated by those skilled in the art that a differential voltage may first be amplified, for example by an operational amplifier in order to provide a higher voltage signal to the processor 300.
• the processor 300 may be configured to enter one or more low power states, such as a sleep state, or powered-off state.
• a low-power state may advantageously reduce the total power draw on the battery 100, thereby extending the useful life of the battery 100.
• the current draw of the electronics 110 may be reduced to less than 10 mA when in the low-power state.
• This low-power state may be enabled by reducing the clock speed of the processor 300, removing power to particular peripherals of the processor 300, reducing the voltage of one or more of the power rails which supply the processor 300 or a combination of the above measures.
• an activation circuit 202 may be configured to generate an interrupt which is configured to switch the processor 300 back into its normal power state, or alternatively simply provide a signal which indicates to the processor 300 that the processor 300 should relay information regarding the battery 100 via the indicator 204.
• the activation circuit 202 may be advantageous for the activation circuit 202 to latch the power to the processor 300, either for a pre-determined period of time, or until a signal is received from the processor 300 which indicates that the processor 300 has completed its task.
• FIG. 4 An exemplary circuit diagram is illustrated in Figure 4 which provides one means for producing a low- cost capacity determination circuit 200 which operates using discrete electronics 110.
• a series of operational amplifiers or comparators 400 are used to illuminate one or more LEDs 402 to provide an indication of the battery voltage and therefore capacity.
• this circuit operates by establishing fixed references 404 on each of the inverting inputs 406 of the comparators 400, and compares these fixed references 404 to a voltage of the power source 102 which is provided to the non-inverting inputs 408 on the comparators 400. When the voltage on the non inverting inputs 408 exceed that of the inverting inputs 406, the output of the comparators 400 goes high and the LEDs 402 are illuminated.
• the specific thresholds for enabling each of the LEDs 402 may therefore be set by varying the values of the resistors in the resistive divider chain 410, or alternatively by providing a different fixed voltage reference 404. It should be appreciated that this example is provided by way of example only, and that alternative means of providing capacity determination using discrete electronics 110 should be apparent to those skilled in the art. Furthermore, specific aspects of this design, such as generating a suitable voltage reference should be well known to those skilled in the art, and may be achieved for example by using a Zener diode or similar reference. It should also be appreciated, that the divider chain 410 illustrated in Figure 4 is provided by way of example only.
• each of the non-inverting 408 inputs may be joined together and have a common connection to the power source 102.
• the switching thresholds will be defined by the reference voltages used on the inverting inputs 406 alone.
• the connections to the inverting 406 and non inverting 408 inputs are somewhat arbitrary, as is the output state of the comparators 400.
• the fixed reference may instead be provided to the non-inverting 408 input, and the power source 102 reference provided to the inverting input 406.
• the indicating LEDs can similarly be rearranged such that they are enabled when the comparator 400 output is low.
• the capacity determination circuit 200 may further be advantageous for the capacity determination circuit 200 to have a low-power consumption. In this way determination of the battery capacity does not in itself cause a significant reduction in the battery capacity. This may be achieved in a number of ways according to various embodiments of the technology.
• the electronic components 110 of the capacity determination circuit 200 may be selected and/or configured in such a manner as to reduce the overall power consumption of the circuit.
• low-power consumption parts may be selected, and voltage divider networks may be configured with high impedance components to reduce the overall power draw.
• the capacity determination circuit 200 may be advantageous to avoid supplying power to the capacity determination circuit 200 when it is not in use. In this way the capacity determination circuit 200 draws reduced power or no power when not actively determining battery capacity.
• the capacity determination circuit 200 may be powered by a common power rail which is switched off and on as required.
• processor 300 it may be advantageous to switch the processor 300 into a low-power operating mode when not actively providing a capacity determination. This may be achieved, for example, by putting the processor 300 into a sleep state until an interrupt is received to revert the processor 300 to the active state.
• the processor 300 is configured to enter the active state based on a signal from an activation circuit 202. Once in the active state, the processor 300 may determine the battery capacity, and relay a signal representative of the capacity to the indicator 204. When this process is complete, the processor 300 may revert to its sleep state once more.
• an activation circuit 202 which is configured to activate a capacity determination circuit 200.
• Using an activation circuit 202 may advantageously reduce the total power consumption of the electronics 110 compared to having a permanently active capacity determination circuit 200, such that the total power draw on the battery 100 is reduced.
• activation circuit 202 refers to the activation circuit 202 as "activating" the capacity determination circuit 200. It should be understood throughout this specification that reference to activation of the capacity determination circuit 200 includes waking the circuit from a low-power or off state and/or providing power to the capacity determination circuit 200.
• the activation circuit 202 may be housed entirely within the housing 108 of the battery 100 as shown in Figure 1. However, this should not be seen as limiting to embodiments of the technology. Housing the electronics 110 entirely within the housing 108 of the battery 100 may in some cases provide a lower-cost solution which can be achieved without requiring any components to be embedded within the battery label 112. In addition, housing the electronics 110 within the housing 108 of the battery 100 may provide a measure of protection against damage.
• activation circuit 202 and/or capacity determination circuit 200 internally to the battery 100 in smart battery applications.
• the activation circuit 202 utilises an input means in the form of a sensor which, following sensing of the appropriate input, triggers the generation of an activation signal.
• the sensor may be an accelerometer, microphone, light sensor, pressure sensor, audio sensor or gyroscope.
• the input means may be touch-based, for example it may include a mechanical, capacitive, inductive or resistive touch interface or button.
• the activation circuit 202 may require a specific sequence of inputs from the sensor prior to activating the capacity determination circuit 200. In this way it may be possible to mitigate the occurrences of unintended activations.
• the predetermined condition or threshold may be configured such that the activation circuit requires two relatively high-amplitude, short-duration acceleration values such as produced by two or more impacts on the battery 100.
• the battery 100 may need to be tapped against a hard surface two or more times to activate the activation circuit 202.
• the activation circuit may further require that a specific sequence of inputs is provided within a predetermined timeperiod, such as within 2 seconds to further reduce the likelihood of unintended activations.
• the activation circuit 202 may be configured with one or more predetermined conditions or thresholds for the sequence of inputs, such as frequency, duration, direction, intensity, or timing.
• the activation circuit 202 may be configured to be activated upon receiving a sequence of inputs which meet one or more predetermined conditions, or exceed one or more predetermined thresholds, relating to signals sensed by the sound sensor, such as frequency, duration, intensity (i.e. volume or amplitude), in order to activate the activation circuit 202.
• the predetermined condition may consist of low thresholds such as requiring that the frequency of the input is below a specific threshold, or occurs for a period of time which is less than a predetermined value.
• the activation circuit may be configured to use pattern recognition methods to recognise patterns in one or more received signals to determine that the sequence of inputs is sufficiently similar (e.g. within certain thresholds of parameters characterising the pattern of input signals) to a predetermined pattern that is required to activate the capacity determination circuit.
• Detection of the required sequence of inputs may be implemented using an appropriately programmed processor 300.
• the processor 300 may be configured to monitor the state of the sensor (or wake on an input from the sensor) to ensure that the inputs are received with the appropriate timing and/or intensity to trigger the activation circuit 202.
• the sensor may be configurable to generate an output signal or interrupt only when the input signal reaches a pre determined threshold based on intensity, direction and/or duration. This approach may advantageously allow the processor 300 to remain in an off-state or low-power state until an appropriate input signal is received.
• detection of the required sequence may be implemented with discrete electronics 110.
• filtering may be applied to the input signal such that input signals containing the desired frequency, duration, intensity and/or sequence are passed to the activation circuit 202, where signals which fall outside the desired parameters are instead attenuated or ignored.
• suitable discrete electronics 110 will depend on the desired activation sequence, and should be apparent to the skilled addressee.
• Figure 5 illustrates a flow diagram of a method of operation of the activation circuit 202 according to one embodiment of the present technology.
• the idle state of the system is for the capacity determination circuit 200 to reside in a sleep state, where the circuit is inactive.
• the circuit checks to see whether the correct sequence of inputs has been provided. If the correct sequence is not provided within a predetermined time period, the electronics 110 return to the sleep state. If the correct sequence is provided, the capacity determination circuit 200 is activated, a determination made, and a signal representative of the determined capacity relayed to the indicator 204. The electronics 110 are then configured to return to the sleep state once more.
• the activation circuit 202 or other components of the technology may be further advantageous for the activation circuit 202 or other components of the technology to disable the capacity determination circuit 200 when a load is being drawn from the power source 102. For example, when the battery 100 is being used in a product. Disabling the capacity determination circuit 200 in this state may advantageously reduce the idle current draw of the battery 100.
• the capacity of the battery 100 is indicated to a user via an indicator 204.
• the indicator may be configured to provide an indication of battery capacity to an appropriate or selected degree of accuracy.
• the indicator may provide a relatively precise indication of capacity, such as a percentage figure for capacity remaining or other quantitative indication, while in other embodiments the indicator may provide an approximate indication of capacity for example a qualitative indication or discrete categorisation of capacity, such as low/medium/high.
• the indicator 204 may be a visual indicator, such as an LED. Flowever, this should not be seen as limiting on embodiments of the technology.
• the indication may additionally or alternatively be provided by audible or tactile feedback using a buzzer, speaker or vibration mechanism.
• the capacity of the battery 100 may be communicated by any number of methods. For example, where an LED is used, a sequence of flashes may be used to indicate the level of charge i.e. five flashes could indicate full charge, three flashes half charge and one flash low or no charge. Alternatively, a multi colour or tri-colour LED could be used, and the colour of the LED could be used to indicate the charge state i.e. green for fully charged, orange for half charged and red for flat.
• Alternative methods of communicating the battery capacity may include a specific sequence or duration of vibrations, beeps, or flashes, sounds, tones, or even synthesised/recorded speech which announces the charge level.
• the battery capacity is communicated by the indicator 204 by means of the battery capacity indicator comprising a suitably programmed processor 300 which is configured to drive the visual/audible/tactile feedback mechanism such as the LED, buzzer, speaker or vibration motor.
• the battery capacity indicator may comprise discrete electronics 110 configured to control the indication mechanism.
• One exemplary implementation of providing a variable pulse sequence is to use a 555-timer. Variations to the number of pulses or pulse rate may be achieved by switching in resistors or capacitors using switching elements such as transistors depending on the detected capacity.
• the circuit illustrated in Figure 4 could be used to drive switching elements of the 555 circuit rather than the LEDs illustrated. Again, selection of suitable discrete electronics 110 will depend on the desired indication sequence and should be apparent to the skilled addressee.
• a visual indicator 204 is used, this is preferably mounted within the housing 108 of the battery 100, however in an alternative embodiment it may be located within or under the label 112 of the battery 100. In embodiments where the visual indicator 204 is mounted within the housing 108 of the battery 100, it may be advantageous to provide a translucent or transparent region of the housing 108 in order to allow light from the visual indicator 204 to be visible to the user.
• the indicator 204 may be configured to relay the capacity information to an external device such as a smartphone, watch, tablet, computer or other external device.
• This relay of information may be achieved using a wireless communication interface configured to transmit information over BluetoothTM, WiFi, NFC or any other suitable wireless network or protocol.
• the indicator 204 may be configured to relay the capacity information via the terminals 104, 106 of the battery 100.
• the indicator 204 may use a two-wire communication protocol such as l 2 C to relay the capacity information to an external device via the terminals 104, 106 of the battery 100.
• the indicator 204 may vary the output voltage on the terminals 104, 106 of the battery 100 to provide an indication of the capacity of the internal power source 102.
• the activation circuit 202 may be configured to disable the input/output electronics 206 or otherwise operatively connect the power source 102 to the battery terminals 104, 106 such that a standard capacity detector may be used.
• the battery 100 may comprise further electrical connections for communicating the battery capacity to an external device.
• the battery label 112 may include an electrically conductive region which provides an electronic signal which is indicative of the capacity of the battery 100.
• This electronic signal may be analogue, for example it may provide a voltage level representative of the battery capacity.
• the electronic may be digital, for example the electronic signal may comprise a series of pulses which indicate the battery capacity.
• Exemplary electronic circuits 110 comprised as part of a battery capacity indicator according to an embodiment of the present technology are illustrated in Figure 6.
• the capacity determination circuit 200 is provided by a resistive divider which includes resistors R17 and R20.
• resistors R17 and R20 As this resistive divider continuously applies a load to the power source 102 it is desirable to have high value resistors to minimise the total current draw; see for example the 1.8 MW and 2.2 MW resistors illustrated by way of example.
• this constant current drawn arrangement is provided by way of example only and in alternative embodiments the voltage divider may be switched in or out of the circuit as required.
• a bipolar junction transistor (BJT) or field-effect transistor (FET) may be positioned between the cell voltage and R17 or alternatively between R20 and the ground connection as would be appreciated by those skilled in the art.
• BJT bipolar junction transistor
• FET field-effect transistor
• a 100 nF capacitor C25 which may assist in filtering the input signal, particularly in relation to any conducted or radiated noise which may interfere with the voltage measurement.
• an activation circuit 202 is also depicted in Figure 6.
• a dedicated integrated circuit namely the BMA253 accelerometer made by Bosch Sensortec; see Ull. It should be appreciated that this IC is one of many possible components which would be suitable in this application.
• this IC includes an interrupt output (pin 5) which can generate an active low signal to wake the processor 300 from its sleep or idle state when sufficient acceleration is detected.
• the accelerometer also includes a l 2 C interface for communicating acceleration values to the processor; see pins 2 and 12 of Ull.
• This embodiment also includes an indicator 204 in the form of an LED (D3).
• This LED is arranged such that an active high signal on pin 18 of the processor results in illumination of the LED.
• LED LED
• other suitable methods of driving an LED as will be apparent to those skilled in the art, may be provided instead or in addition.
• the activation circuit 202 On detection of a double-tap sequence, the activation circuit 202 generates an interrupt which wakes the processor 300 if the processor is not already in an active state;
• the processor 300 measures the voltage on pin 4 which is indicative of the power source 102 voltage
• the processor 300 determines what the state of charge of the power source 102, using pre-programmed voltage reference values.
• the processor 300 activates the indicator 204 with a suitable sequence of LED flashes according to the measured capacity.
• One exemplary flash sequence may be:
• the above flash sequence is provided by way of example only and any other suitable sequence of flashes that is able to convey a variety of levels of power capacity may be used in alternative embodiments of the present technology.
• the selective illumination of different colour lights may be used to indicate different power capacity levels.
• the selective illumination of a light source at different intensity levels may be used to indicate different power capacity levels.
• the activation circuit 202 may simply be a part of the capacity determination circuit 200.
• the technology may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

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• 2020
  • 2020-08-04 WO PCT/NZ2020/050081 patent/WO2021025561A1/en not_active Ceased
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