A battery unit changeable between a first active mode and a second active mode

Abstract

There is provided a battery unit for an aerosol generation device, wherein the battery unit is changeable between a first active mode and a second active mode, wherein in the second active mode a characteristic of the battery unit is derated relative to the first active mode to limit operation of the battery unit to prolong longevity of the battery unit.

Description

[0001] A battery unit changeable between a first active mode and a second active mode

[0002] The present disclosure relates to a battery unit for an aerosol generation device, an aerosol generation system, and a method of controlling the usage of a battery unit in an aerosol generation device.

[0003] Background

[0004] As the demand for aerosol generation devices increases, so does the need for improved battery systems. There are growing sustainability efforts which mean that there are goals to prolong battery lifetimes to reduce requirements to replace batteries in electronic devices, such as aerosol generation devices.

[0005] Current battery systems for aerosol generation systems typically have as large a power capacity as possible, in order to minimise the frequency of charging sessions required from a user. Due to this arrangement, each charging session may last long periods of time in order to fully charge the battery system. As the battery reaches higher states of charge, the rate of charging dramatically slows.

[0006] Further, it can be inconvenient for a user to need to replace the battery of an aerosol generation device, which can potentially be avoided.

[0007] A challenge associated with the above is providing a battery unit and device that meets growing sustainability demands while providing convenient operation for a user.

[0008] It is the object of the invention to overcome or avoid at least some of the above-referenced problems, or to provide an alternative approach.

[0009] Summary

[0010] According to the present disclosure there is provided an aerosol generation system including an aerosol generation device and a battery unit including the features as set out in the claims.

[0011] In one example, there is provided an aerosol generation system including an aerosol generation device and a battery unit for an aerosol generation device, wherein the battery unit is changeable between a first active mode and a second active mode, wherein in the second active mode a charging characteristic of the battery unit is derated relative to the first active mode to limit operation of the battery unit to prolong longevity of the battery unit.

[0012] Providing an option to derate a charging characteristic of the battery unit enables the user to selectively extend the longevity of the battery unit. That is to say that a user may wish to operate the aerosol generation device in a first active mode in which it operates according to normal specifications or a second active mode in which a charging characteristic of the battery unit is reduced. In other words, the battery unit may have a first operation window when operating in the first active mode and a second operation window when operating in the second active mode.

[0013] Prolonging longevity of the battery unit is not merely a reference to the remaining amount of time that the battery unit can be used based on the charge remaining in the current session, but rather, the overall life of the battery unit across multiple charge cycles.

[0014] In one example, the derated characteristic comprises a rate of charge of the battery unit. That is, the battery unit may limit the rate at which it may be charged. In some examples, the processor of the aerosol generation device (or charging unit) may limit the rate of charge of the battery unit. Reducing the rate of charge reduces degradation of the battery unit and so extends lifespan of a battery unit. Further, often a user may charge the battery unit overnight and so reducing the rate of charge does not reduce the user experience.

[0015] In one example, in the second active mode the rate of charge of the battery unit is limited to an upper threshold rate of charging of approximately 33% of the maximum rate of charge of the battery unit. This enables an extension of battery unit lifespan.

[0016] In one example, the derated characteristic comprises a state of charge of the battery unit. Charing the battery unit to 100% capacity increases degradation of the battery unit and so reducing the obtainable state of charge of the battery unit increases the overall lifespan of the battery unit.

[0017] In one example, in the second active mode the state of charge of the battery unit is limited to an upper threshold state of charge of approximately 50% of the maximum state of charge capacity of the battery unit. This enables an extension of battery unit lifespan. In one example, in the second active mode the state of charge of the battery unit is limited to be below an upper threshold state of charge that is dependent upon an age of the battery unit. The age of the battery unit may be measure in number of charging cycles or time spent being charged. As battery units age, the obtainable state of charge may reduce and so providing an upper threshold that also reduces with age will prolong the lifespan of the battery unit.

[0018] In one example, in the second active mode the state of charge of the battery unit is limited to be above a lower threshold state of charge. Prolonged exposure of the battery unit at very low state of charge would potentially increase degradation of the battery unit and so providing a lower threshold in which the battery unit stops providing charge would prolong the lifespan of the battery unit.

[0019] In one example, the lower threshold of the state of charge is dependent upon an age of the battery unit. Retaining a battery unit at zero charge may degrade the battery unit with time. As the battery unit ages, increasing the lower threshold of the state of charge is helpful to reduce degradation of the battery unit.

[0020] In one example, usage data of the battery unit is tracked, and the derated charging characteristic is dependent on the usage data. In this example the derated charging characteristic in the second active mode may be selected to provide the least disruption to a user. For example, if the usage data indicates that the battery unit is typically charged at night, then the selected derated characteristic may be the charging rate as fast charging would not be necessary as a slow charge would not negatively impact a user experience.

[0021] In one example, the derating charging characteristic comprises a charging voltage. Limiting the charging voltage reduces degradation of the battery unit.

[0022] In one example, the battery unit comprises an indicator to indicate to a user if the battery unit is in the first active mode or the second active mode. The indicator provides a means for a user to identify which state the battery unit is in. In some examples, the indicator is on the aerosol generation device instead of / in addition to the battery unit.

[0023] In one example, the battery unit is configured to switch between the first active mode and the second active mode upon receipt of a user input. In this example, the user can selectively control the operation of the battery unit to switch between the first active mode and the second active mode and visa-versa.

[0024] In one example, aerosol generation device comprises an energy provision system; and a controller to control the battery unit.

[0025] In one example, the battery unit is configured to select the charging characteristic for derating and / or to adjust the level of derating. That is, the battery unit and / or processor of the aerosol generation device may be able to automatically adjust the derating charging characteristic or the level of derating depending on the usage data to optimise conditions to reduce battery unit degradation.

[0026] In one example, the battery unit is changed between the first active mode and the second active mode by operation of the controller of the aerosol generation device. That is, the controller of the aerosol generation device may control input to and / or output from the battery unit such that it operates in the first active mode or the second active mode. For example, the controller of the aerosol generation device may control one or more of rate of charge, state of charge, state of vaping, charging voltage, or the battery unit. The controller may effectively put the battery unit in a first active mode or second active mode.

[0027] In one example, derated charging characteristic means a reduction of between 10% to 50% from the first active mode to the second active mode. In examples, this may be 10%, 15%, 20%, 25%, 30%, 33%, 35%, 40%, 45% or 50%. Further specific examples are provided below.

[0028] In one example, there is provided a method of controlling the usage of a battery unit for an aerosol generation device comprising: switching between a first active mode and a second active mode, wherein in the second active mode a charging characteristic of the battery unit is derated with respect to the first active mode.

[0029] In one example, there is provided a battery unit for an aerosol generation device, wherein the battery unit is changeable between a first active mode and a second active mode, wherein in the second active mode a characteristic of the battery unit is derated relative to the first active mode to limit operation of the battery unit to prolong longevity of the battery unit. The characteristic may comprise a charging characteristic of the battery unit.

[0030] Providing an option to derate a (e.g., electrical or power) characteristic of the battery unit enables the user to selectively extend the (e.g. electrical or power) longevity of the battery unit. That is to say that a user may wish to operate the aerosol generation device in a first active mode in which it operates according to normal specifications or a second active mode in which a (e.g., electrical or power) characteristic of the battery unit is reduced. In other words, the battery unit may have a first operation window when operating in the first active mode and a second operation window when operating in the second active mode.

[0031] In one example, the derated characteristic comprises a rate of charge of the battery unit. That is, the battery unit may limit the rate at which it may be charged. In some examples, the processor of the aerosol generation device (or charging unit) may limit the rate of charge of the battery unit. Reducing the rate of charge reduces degradation of the battery unit and so extends lifespan of a battery unit. Further, often a user may charge the battery unit overnight and so reducing the rate of charge does not reduce the user experience.

[0032] In one example, in the second active mode the rate of charge of the battery unit is limited to an upper threshold rate of charging of approximately 33% of the maximum rate of charge of the battery unit. This enables an extension of battery unit lifespan.

[0033] In one example, the derated characteristic comprises a state of charge of the battery unit. Charing the battery unit to 100% capacity increases degradation of the battery unit and so reducing the obtainable state of charge of the battery unit increases the overall lifespan of the battery unit.

[0034] In one example, in the second active mode the state of charge of the battery unit is limited to an upper threshold state of charge of approximately 50% of the maximum state of charge capacity of the battery unit. This enables an extension of battery unit lifespan.

[0035] In one example, in the second active mode the state of charge of the battery unit is limited to be below an upper threshold state of charge that is dependent upon an age of the battery unit. The age of the battery unit may be measure in number of charging cycles or time spent being charged. As battery units age, the obtainable state of charge may reduce and so providing an upper threshold that also reduces with age will prolong the lifespan of the battery unit. In one example, in the second active mode the state of charge of the battery unit is limited to be above a lower threshold state of charge. Prolonged exposure of the battery unit at very low state of charge would potentially increase degradation of the battery unit and so providing a lower threshold in which the battery unit stops providing charge would prolong the lifespan of the battery unit.

[0036] In one example, the lower threshold of the state of charge is dependent upon an age of the battery unit. Retaining a battery unit at zero charge may degrade the battery unit with time. As the battery unit ages, increasing the lower threshold of the state of charge is helpful to reduce degradation of the battery unit.

[0037] In one example, the derated characteristic comprises a battery unit operating temperature, wherein the battery unit is configured to operate in a battery unit operating temperature window which comprises an upper temperature threshold and a lower temperature threshold. The battery unit and / or aerosol generation device may comprise an indicator to indicate to the user if the battery unit is operating outside of the battery unit operating temperature window. Using the battery unit outside of the battery unit operating temperature window can contribute to the degradation of the battery unit and so indicating to a user that the battery unit is outside of this window provides the user with an opportunity to extend the life of the battery unit.

[0038] In one example, the upper and / or lower temperature threshold may be dependent upon an age of the battery unit. That is the upper temperature threshold may be reduced and the lower temperature threshold may increase with use of the battery unit.

[0039] In one example, the derated characteristic comprises a discharge current of the battery unit. Limiting the discharge current reduces degradation of the battery unit. That is to say, that the battery unit may be adjusted such that it limits the amount of discharge current that can be provided by it. In some examples, the processor of the aerosol generation device may limit the amount of discharge current from the battery unit when it is in the second active mode.

[0040] In one example, usage data of the battery unit is tracked, and the derated characteristic is dependent on the usage data. In this example the derated characteristic in the second active mode may be selected to provide the least disruption to a user. For example, if the usage data indicates that the battery unit is typically charged at night, then the selected derated characteristic may be the charging rate as fast charging would not be necessary as a slow charge would not negatively impact a user experience.

[0041] In one example, there is provided an aerosol generation system comprising a battery unit and an aerosol generation device, wherein the aerosol generation device comprises an energy provision system; and a controller.

[0042] In one example, there is provided a method of controlling the usage of a battery unit for an aerosol generation device comprising: switching between a first active mode and a second active mode, wherein in the second active mode a characteristic of the battery unit is derated with respect to the first active mode.

[0043] The above referenced features may be combined in various combinations.

[0044] Brief Description of the Drawings

[0045] Examples of the present disclosure will now be described with reference to the accompanying drawings.

[0046] Figure 1 shows a schematic example of an aerosol generation system comprising a battery unit in an aerosol generation device;

[0047] Figure 2 shows a graph of an example of a first charging rate and a second charging rate;

[0048] Figure 3 shows a graph of an example of the battery unit capacity retention against number of charging cycles in a first active mode and a second active mode;

[0049] Figure 4 shows graph representing state of charge of the battery unit in a first active mode and second active mode; and

[0050] Figure 5 shows an example of an external charger unit suitable for charging and / or holding the aerosol generation device including the battery unit.

[0051] Detailed Description As used herein, the term “aerosol precursor material”, “vapour precursor material” or “vaporizable material” are used synonymously and may refer to a material and / or composition, which may for example comprise nicotine or tobacco and a vaporising agent. The aerosol precursor material is configured to release an aerosol when heated or otherwise mechanically stimulated (such as by vibrations). Tobacco may take the form of various materials such as shredded tobacco, granulated tobacco, tobacco leaf and / or reconstituted tobacco. Nicotine may be in the form of nicotine salts. Suitable vaporising agents include: a polyol such as sorbitol, glycerol, and glycols like propylene glycol or triethylene glycol; a non-polyol such as monohydric alcohols, acids such as lactic acid, glycerol derivatives, esters such as triacetin, triethylene glycol diacetate, triethyl citrate, glycerin, or vegetable glycerin. In some examples, the aerosol precursor material is substantially a liquid or a gel that holds or comprises one or more solid particles, such as tobacco particles extracted from tobacco materials or suspended in a solution or gel.

[0052] An aerosol generation device is configured to aerosolise an aerosol precursor material without combustion in order to facilitate delivery of an aerosol to a user. Furthermore, and as is common in the technical field, the terms “vapour” and “aerosol”, and related terms such as “vaporize”, “volatilize” and “aerosolise”, may generally be used interchangeably.

[0053] As used herein, the term “aerosol generation device” is synonymous with “aerosol generating device” or “device” and may include a device configured to heat an aerosol precursor material and deliver an aerosol to a user, typically without combusting the aerosol precursor material. The device may be portable. “Portable” may refer to the device being for use when held by a user. The device may be adapted to generate a variable amount of aerosol, which can be controlled by a user input.

[0054] As used herein, the term “aerosol” may include a suspension of vaporizable material as one or more of: solid particles; liquid droplets; gas. Said suspension may be in a gas including air. Aerosol herein may generally refer to / include a vapour. Aerosol may include one or more components of the vaporizable material.

[0055] The disclosure generally relates to the ability to improve battery unit longevity, increase safety, and reduce inconvenience associated with battery unit replacement. Further, the disclosure provides further miniaturisation of aerosol generation devices and battery units that provide electric power to them. In addition, it relates to methods for extending the usable life of the battery, whilst also ensuring that they provide sufficient power to the aerosol generation device to provide a desired user experience.

[0056] Figure 1 shows an example of an aerosol generation system including an aerosol generation device 200 and a battery unit 100. The aerosol generation device 200 may also include a controller 202 (otherwise known as a processor or control unit) that is configured to control operation of the aerosol generation device 200, in use.

[0057] The aerosol generation device 200 may also include a chamber 204 for receiving a consumable comprising aerosol precursor material (now shown). The aerosol precursor material may be in a solid form or a liquid form.

[0058] The aerosol generation device 200 may also comprise an energy provision system 206, such as a heater configured to heat the consumable. The energy provision system 206 could take any form configured to provide energy to the consumable to generate aerosol from the consumable. For example, it could take the form of a resistive or inductive heater or the like. It may also comprise a wick and coil arrangement configured to absorb liquid aerosol precursor material and generate an aerosol. Other arrangements of the energy provision system and the aerosol generation device are envisaged.

[0059] The battery unit 100 is changeable between a first active mode and a second active mode, in use. That is to say, the battery unit 100 is configured to enable the user to selectively switch the battery unit 100 between the first active mode and the second active mode, whether the battery unit 100 is in use, e.g., the aerosol generation device 200 is handheld by the user, or the battery unit 100 and aerosol generation device 200 is docked in a charging station. In both the first active mode and the second active mode, the aerosol generation device 200 may be usable to generate an aerosol from the consumable and / or in a state of being charged. That is to say that neither the first active mode nor the second mode is a sleep mode or an idle mode in which the battery unit 100 is configured to be in a “sleep state” or “idle state” in which the power is minimised to a level that supports controls, but not sufficient to generate an aerosol from the consumable. In contrast, the first active mode and the second active mode still provide sufficient power to generate an aerosol from the consumable. In other words, in the second active mode the battery unit delivers power that is below the potential power that the battery unit could deliver at that time - it is being deliberately derated for the purpose of prolonging overall battery life across the life of the battery. In some examples, the first active mode and the second active mode relate to charging rates / state of charge, as will be described in more detail below. In some examples, the battery unit 100 is changeable between the first active mode and the second active mode by the controller 202 of the aerosol generation device 200.

[0060] In examples, the derated characteristic relates to charging. That is to say that the derated characteristic may include charging rates, state of charge, charging voltage, state of vaping or the like.

[0061] The first active mode and the second active move may be a first energy management scheme and a second energy management scheme respectively. The first active mode and the second active move may be a first operation protocol and a second operation protocol respectively.

[0062] In the second active mode a characteristic of the battery unit 100 is derated relative to the first active mode to limit operation of the battery unit 100 to prolong longevity of the battery unit. That is, in one example not relating to a derated charging characteristic, the battery unit 100 may be changeable, in use, to alter the provision of electric power to the aerosol generation device between a first active mode and a second active mode. For example, in the first active mode the battery unit 100 is configured to provide a first electric power level to the aerosol generation device 200, in use and in the second active mode, the battery unit 100 is configured to provide a second electric power level to the aerosol generation device 200. Providing a first electric power level or a second electric power level to the aerosol generation device 200 is not a charging characteristic, but rather an electric power delivery characterstic. As mentioned above, both the first electric power level and the second electric power level are sufficient to supply the heater with enough electric power to generate an aerosol from the consumable to enable a user to use the aerosol generation device 200.

[0063] The aerosol generation device 200 may include an input that enables the user to change the battery unit 100 between the first active mode and the second active mode, in use. For example, the aerosol generation device may comprise a button 210 that can be pressed by a user to switch the battery unit 100 between the first active mode and the second active mode (and visa-versa), in use. The aerosol generation device 200 may provide an indication to the user whether the device 200 is operating in the first active mode or the second active mode, for example, by haptic feedback or illumination of lights. In the example shown in figure 1 , the aerosol generation device includes an indicator 208 to indicate whether the battery unit 100 is int the first active mode or the second active mode to the user.

[0064] In some examples, the controller 202 of the aerosol generation device 200 may be used to control the battery unit 100 to operate in the first active mode or the second active mode.

[0065] In one example, the derated characteristic comprises a rate of charge of the battery unit 100. That is that in the first active mode the battery unit 100 is configured to be charged at a first charging rate and in the second active mode the battery unit 100 is configured to be charged at a second charging rate, which is lower than the first charging rate. The charging rate of a battery contributes to the usable lifespan of the battery unit. That is to say that if the battery unit is regularly charged at a relatively high charging rate, then it will degrade at a faster rate when compared with charging a battery unit at a lower rate. As such, providing an option for the battery unit 100 to be charged at the second charging rate provides the user with an option for reducing degradation of the battery unit to enable the battery unit’s usable lifespan to be increased.

[0066] In some circumstances, the user may require relatively fast charging and so select the first charging rate at which to charge the battery unit 100. For example, in a situation where the user needs to leave a charging point and intends to use the aerosol generation device 200. In other examples, the user may not be under time pressure, for example when they charge the aerosol generation device 200 overnight. In this case, the user may switch the battery unit 100 to be in the second active mode in which the battery unit 100 is charged at the second charging rate. In examples, the battery unit 100 may limit the charging rate by limiting the charging current that contributes to charging the battery unit 100. That is to say that the charging current is reduced due to maximum charging voltage being reached (internal resistance of the battery is limiting internal factor). In this case, the second active mode may set a voltage operation window and so the charging current must drop due to the charging voltage at the top of the voltage operation window being reached.

[0067] Figure 2 shows an example of the first charging rate, indicated by curve 302, and a second charging rate, indicated by curve 304. The y-axis is indicative of the state of charge of the battery unit 100 and the x-axis represents time. As shown in figure 2, the first charging rate is designed to charge the battery unit 100 at a faster rate when compared with the second charging rate. Figure 3 shows a graph of the battery unit capacity retention against number of charging cycles. Line 306 represents the change in capacity retention of a battery unit 100 when subject to the second charging rate and line 308 represents the change in capacity retention of a battery unit 100 when subject to the first charging rate. In other words, the battery unit capacity retention reduces more when subject to the relatively high first charging rate.

[0068] In one example, in the second active mode the rate of charge of the battery unit is limited to an upper threshold rate of charging of approximately 33% of the maximum rate of charge of the battery unit, more preferably 25%, more preferably 20%, more preferably 15% or lower. For example, in the first active mode the battery unit may be charged from 0% charge to 100% charge in 2 hours, whereas in the second active mode (in which the upper threshold rate of charging of approximately 33%), the battery unit may be charged from 0% charge to 100% charge in 6 hours. Reducing the charging rate may be implemented by reducing the charging current. In general, the slower maximum rate of charge, the less degradation that the battery unit will experience. As described in more detail below, if usage data is indicative of the battery unit 100 being left on charge for longer periods of time, then the upper threshold rate of charging can be adjusted accordingly so as to optimise the charging rate.

[0069] In one example, the derated characteristic comprises a state of charge of the battery unit 100. That is to say that in the first active mode, the battery unit is capable of being charged to a first charge level, whereas in the second active mode, the battery unit is capable of being charged to a second charge level, which is lower than the first charge level.

[0070] Figure 4 shows an example of a curve 310 representing state of charge of the battery unit 100 in the first active mode and second active mode. In this mode, the battery unit 100 may be charged to a maximum possible level (accounting for degradation of the battery unit). Curve 312 is representative of the charging of the battery unit when in a second active mode (in this example). In this case, the state of charge of the battery unit is limited to an upper threshold state of charge when operating in the second active mode. That is that once the battery unit 100 reaches the upper threshold, then it stops receiving additional charge. For example, the controller 202 of the aerosol generation device 200 may monitor the state of charge of the battery unit 100 and prevent further charge being provided to the battery unit 100 once the upper limit is reached. In other examples, the battery unit 100 may have an internal monitoring system to monitor the level of charge and prevent further charging once the upper limit is reached. In one example, the upper threshold is approximately 50% of the maximum state of charge capacity of the battery unit 100. An upper threshold of approximately 50% provides a compromise between reduction of ageing and potential lost aerosol generation opportunity. More preferably, the upper threshold is 40%, more preferably 30%, more preferably 20%. The lower the upper threshold, the more prolonged the overall life of the battery unit 100 will be. In one example, in the second active mode, the battery unit 100 is derated in both charging rate (as shown in figure 2) and also state of charge (as shown in figure 4).

[0071] In one example, in the second active mode the state of charge of the battery unit 100 is limited to be below an upper threshold state of charge that is dependent upon an age of the battery unit. As shown in Figure 3, the capacity retention of the battery unit may decrease with the number of cycles of charge that the battery unit 100 has been subjected too. As such, the “maximum” state of charge achievable by the battery unit 100 reduces with age.

[0072] In this disclosure “state of vaping” is used to define a metric that takes number of sessions or number of puffs into account. For example, 100% state of vaping the battery unit 100 is at maximum capacity and is capable of providing the maximum number of aerosol generation sessions. 0% state of vaping means that the battery unit is incapable of providing sufficient electric power for a whole aerosol generation session. For example, the controller 202 comprises information on the required level of battery unit 100 charge to provide a single aerosol generation session and if the battery unit 100 has less charge than this level, the battery unit would be considered to be at 0% state of vaping. In some examples, state of vaping takes into account the reduction in battery capacity due to ageing. That is to say that 100% state of vaping of a new battery is different to a 100% state of vaping of an aged battery that has suffered some degradation.

[0073] In some examples, in the second active mode, the battery unit 100 is only chargeable such that the battery unit 100 is limited to an upper threshold of 90% state of vaping, more preferably 80% with increased ageing.

[0074] The ageing of the battery unit 100 may be actively monitored by the device by internal algorithms. In one example, the increased ageing referred to above corresponds to 400 cycles (annual usage with approximately one charge per day). However, 500 cycles, 600 cycles or 700 cycles may also be envisaged as being indicative of ageing. 700 cycles may be indicative of 2 years of usage with capacity retention of at least 80%. As ageing (the battery unit’s capacity retention or remaining capacity indication) may be actively monitored, even if the device is not much cycled but ages due to other means such as extended time experienced at a high temperature (e.g., 50°C and above), this can be accounted for.

[0075] In some examples, in the second active mode, the battery unit 100 also has a lower limit such that the battery unit stops providing electric power once the state of vaping level reaches a lower threshold with increased ageing. In one example, the lower threshold is a 10% state of vaping, more preferably a 15% state of vaping with increased ageing. That is, once the lower threshold is reached, the battery unit 100 stops actively supplying power to the heater (or equivalent) of the aerosol generation device 200. At this stage, the user would have the opportunity to switch back to the first active mode to continue the aerosol generation session, if desired. It has been found that avoiding situations where the battery unit 100 is entirely drained of charge reduces battery capacity degradation. Ageing may be determined as explained above.

[0076] In some examples, in the second active mode, the battery unit 100 is only chargeable such that the battery unit 100 is limited to an upper threshold of 90% state of charge, more preferably 80% state of charge with increased ageing. Ageing may be determined as explained above.

[0077] In some examples, in the second active mode, the battery unit 100 also has a lower limit such that the battery unit stops providing electric power once the state of charge level reaches a lower threshold. In one example, the lower threshold is a 10% state of charge, more preferably a 15% state of charge, more preferably 20% state of charge. That is, once the lower threshold is reached, the battery unit 100 stops actively supplying power to the heater (or equivalent) of the aerosol generation device 200. As described above, providing this lower limit increases the longevity of the battery unit life by reducing battery unit degradation.

[0078] In one example, the lower threshold of the state of charge is dependent upon an age of the battery unit 100. In one example, the lower threshold of the state of charge is dependent upon a number of charging sessions that the battery unit 100 has been subjected to. For example, the battery unit 100 (or controller 202) may monitor the number of discrete charging sessions or the total number of charging hours that the battery unit receives 100. Once the number of discrete charging sessions or the total number of charging hours reaches a threshold number, then the lower threshold state of charge is increased, for example to 15% or 20% state of charge.

[0079] In one example, the derated characteristic comprises a battery unit operating temperature. This is not a charging characterstic. That is, in the second active mode, the battery unit 100 is only configured to supply electric power if the internal temperature of the battery unit 100 is within the specified operating range. If the internal temperature of the battery unit moves outside of this range, then the battery unit 100 stops supplying electric power to the aerosol generation device 200. In some examples, in this case an indication may be provided by the aerosol generation device that the battery unit 100 is outside of its temperature operating range. The battery unit operating temperature window comprises an upper temperature threshold and a lower temperature threshold. The upper and / or lower temperature threshold may be dependent upon an age of the battery unit 100. That is, as described above, the “age” of the battery unit 100 may be inferred from the number of discrete charging session that it has received or the time that is has been subject to charging. The upper temperature threshold may be reduced dependent on the number of discrete charging session that it has received or the time that is has been subject to charging. Further the lower temperature threshold may be increased dependent on the number of discrete charging session that it has received or the time that is has been subject to charging. In one example, the lower temperature threshold is -5 degrees Celsius, which may increase to 5 degrees Celsius with battery ageing. In one example, the upper temperature threshold is 55 degrees Celsius, which may decrease to 45 degrees Celsius with battery ageing. Ageing may be determined as explained above.

[0080] Again, the user could switch to the first active mode if they wish to continue with the aerosol generation session. Operating the battery unit outside of the ideal temperature window can increase the degradation of the battery unit and so providing the second active mode increases the usable life of the battery unit 100.

[0081] In one example, the derated characteristic comprises a discharge current of the battery unit 100. This is not a charging characteristic. That is in the second active mode, the battery unit 100 is limited to provide a maximum discharge current of an upper threshold current. That is, the heater 206 would take longer to heat up to the desired temperature when operating in the second active mode. Limiting the maximum discharge current would reduce battery degradation. For example, the discharge current may be de-rated to between 50% to 75% of the discharge current of the first active mode. For example, the discharge current may be reduced in the second active mode such that a pre-heating time is increased to approximately 30-40 seconds compared with only 20 seconds of the first active mode.

[0082] In one example, usage data of the battery unit 100 is tracked and the derating characteristic is dependent on the usage data. For example, the battery unit 100 and / or controller 202 may track usage data throughout the day and / or week and automatically adjust derating characteristics to prolong battery unit life. For example, it may be determined that the battery unit is typically charged through the night and so the second active mode may limit the maximum rate of charge of the battery unit 100 during the night so as to prolong the overall life of the battery unit.

[0083] Alternatively, the usage data may indicate that on a particular day, the aerosol generation device is not expected to be used much and so the second active mode may comprise derating the maximum state of charge to a lower threshold value for that particular day.

[0084] The usage data may comprise the typical time that the battery unit receives charge. This usage data may then determine the upper threshold for the charging rate such that the charging rate can be minimised whilst still providing a high State-of-Charge as late as possible (late here means directly before the consumer disconnects the battery unit from charger).

[0085] The usage data may also provide information to switch the battery unit to the second active mode early if the consumer is not expected to charge soon but they are expected to use the device extensively e.g., during next day.

[0086] The battery unit 100 (and / or controller 202) may monitor the battery ageing (e.g., capacity retention, number of aerosol sessions per full battery charge) and adjust the derated characteristics accordingly.

[0087] Figure 5 shows an example of an external charger unit 300 suitable for charging and / or holding the aerosol generation device 200 including the battery unit 100, in use. The charger unit 300 may be a portable charging device suitable for charging the battery unit 100 in a portable manner.

[0088] In this architecture, the aerosol generation device 200 may often simply be reinserted into the charger unit 300 after use and in-between sessions. In this scenario, the battery unit 100 may be maintained at a full state of charge for a significant amount of time, which negatively impacts battery life and is not desired. This is especially relevant to battery developments in consumer electronics where the maximum battery voltage (at full state-of-charge) is above 4.2V to achieve higher energy densities (and further miniaturization). Note that this is also applicable to battery units with a maximum voltage of 4.2V or lower.

[0089] In some examples, the battery unit 100 (or controller 202) may sense that the aerosol generation device 200 has been placed in a charger unit 300 and limit the maximum voltage that the battery may obtain to a threshold maximum voltage. Alternatively, the battery unit 100 (or controller 202) may sense that the aerosol generation device 200 has been placed in a charger unit 300 and limit the maximum voltage that the battery may obtain to a threshold state of charge.

[0090] In one example, the usage data of the battery unit 100 is tracked to determine a desired charging profile. The battery unit 100 (and / or controller 202) may not initiate maximum voltage charging before a certain time. For example, if the first session in a day for the consumer is expected at 8am, then charging of the battery unit 100 to maximum voltage is not activated before 7am. Before this time the battery unit 100 may be charged according to the following formula:

[0091] Charging voltage = Maximum charging voltage - coefficient (ageing).

[0092] The coefficient is dependent on age of the battery unit and may be determined according to one of the methods outlined above (e.g., number of charging cycles, maximum measured battery capacity, time subject to charging, etc.)

[0093] The coefficient (ageing) may be in the range of 0.1V to 0.2V for relatively new battery units 100. Once the battery unit start significantly ageing (e.g., if the battery capacity retention falls below 90%) the coefficient is increased. A look-up table may be implemented in the controller 202. The look-up table may be updated as needed.

[0094] One example of the look-up table values is copied below:

[0095] 100 - 90% battery unit capacity retention — > coefficient (ageing) = 0.1V 90 - 80% battery unit capacity retention — > coefficient (ageing) = 0.15V 80 - 70% battery unit capacity retention — > coefficient (ageing) = 0.2V Below 70% battery unit capacity retention — > coefficient (ageing) = 0.25V

[0096] Reducing the maximum battery voltage prolongs the battery life and aids with battery unit 100 miniaturisation.

[0097] In one example, the battery unit 100 and / or aerosol generation device 200 includes an indicator 208 to indicate to a user if the battery unit 100 is in the first active mode or the second active mode. The indicator may be a light indicator or haptic feedback or the like to indicate the state of the battery unit 100 to the user. In one example, the battery unit 100 is configured to switch between the first active mode and the second active mode upon receipt of a user input. For example, the battery unit 100 may include an input for receiving an operator input. In some examples, the aerosol generation device 200 may include an input, such as a button, slider or interactive sensor 210 for receiving the user input and transmitting this input to the battery unit 100 to switch the battery unit 100 between the first active unit and the second active unit and vice versa.

[0098] In one example, the battery unit 100 (or controller 202) is configured to select the characteristic for derating and / or to adjust the level of derating.

[0099] In one example, as shown in Figure 1 , the aerosol generation device 200 includes the energy provision system 206, the controller 202 and the battery unit 100 as described above.

[0100] The controller 202 is configured to control the battery unit 100. That is to say that the controller 202 (also referred to as processor) controls the battery unit 100 to switch between the first active mode and the second active mode. The controller 202 may be able to select which characteristic to de-rate based on user input or based on pre-configured settings of the aerosol generation device. The controller 202 may be configured to provide input to the battery unit to control the extent to which the characteristic is de-rated. That is to say that in the example of the derated characteristic comprising a rate of charge of the battery unit 100, the controller 202 may limit an upper threshold rate of charging, for example to approximately 33% of the maximum rate of charge of the battery unit 100. The controller 202 may include an integrated circuit and / or charge controller for this purpose. The integrated circuit and / or charge controller could be used to control the relevant charging characteristic of the battery unit in the first active mode and the second active mode. The controller 202 may also be configured to control monitor the charging characteristic. For example, the controller 202 may limit the upper threshold rate of charging, the upper threshold state of charge, the lower threshold state of charge, the charging voltage etc. as described above. The controller 202 may limit these to specific percentages / rates as specific in this description.

[0101] In one example, there is a method of controlling the usage of a battery unit 100 for an aerosol generation device 200. The method comprises switches between a first active mode and a second active mode, wherein in the second active mode a characteristic of the battery is derated with respect to the first active mode. The second active mode reduces degradation of the battery unit 100.

[0102] Although preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims and as described above.

Claims

CLAIMS1. An aerosol generation system comprising: an aerosol generation device; and a battery unit, wherein the battery unit is changeable between a first active mode and a second active mode, wherein in the second active mode a charging characteristic of the battery unit is derated relative to the first active mode to limit operation of the battery unit to prolong longevity of the battery unit.

2. The system according to claim 1 , wherein the derated charging characteristic comprises a rate of charge of the battery unit.

3. The system according to claim 2, wherein in the second active mode the rate of charge of the battery unit is limited to an upper threshold rate of charging of approximately 33% of the maximum rate of charge of the battery unit.

4. The system according to any one of the preceding claims, wherein the derated charging characteristic comprises a state of charge of the battery unit.

5. The system according to claim 4, wherein in the second active mode the state of charge of the battery unit is limited to an upper threshold state of charge of approximately 50% of the maximum state of charge capacity of the battery unit.

6. The system according to claim 4, wherein in the second active mode the state of charge of the battery unit is limited to be below an upper threshold state of charge that is dependent upon an age of the battery unit.

7. The system according to claim 6, wherein in the second active mode the state of charge of the battery unit is limited to be above a lower threshold state of charge.

8. The system according to any one of the preceding claims, wherein usage data of the battery unit is tracked, and the derating charging characteristic is dependent on the usage data.

9. The system according to claim 8, wherein the derating charging characteristic comprises a charging voltage.

10. The system according to any one of the preceding claims, comprising an indicator to indicate to a user if the battery unit is in the first active mode or the second active mode.

11. The system according to any one of the preceding claims, wherein the battery unit is configured to switch between the first active mode and the second active mode upon receipt of a user input.

12. The system according to any one of the preceding claims, wherein the aerosol generation device comprises: an energy provision system; and a controller to control the battery unit.

13. A battery unit for an aerosol generation device, wherein the battery unit is changeable between a first active mode and a second active mode, wherein in the second active mode a charging characteristic of the battery unit is derated relative to the first active mode to limit operation of the battery unit to prolong longevity of the battery unit.

14. A method of controlling the usage of a battery unit for an aerosol generation device comprising: switching between a first active mode and a second active mode, wherein in the second active mode a charging characteristic of the battery unit is derated with respect to the first active mode.

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