Charging Safety Cutoff

Abstract

The present invention relates to a method for charging a battery in an aerosol generating system, the method including the steps of initiating charging of the battery, monitoring an electrical parameter indicative of a charging rate of the battery, determining a charging rate of the battery, comparing the determined charging rate with a reference charging rate, and inhibiting the battery from being charged if the charging rate deviates from the reference charging rate. The present invention also relates to a charging controller for the aerosol generating system. The present invention also relates to an aerosol generating device comprising the charging controller, and a charging case for the aerosol generating device comprising the charging controller.

Description

[Technical field]

[0001] The present invention relates to a method for safely charging a battery in an aerosol generating system, and to an aerosol generating system implementing said method. The present invention also relates to a case, an aerosol generating device, and a charging case for use in the aerosol generating system. [Background technology]

[0002] Generally, known aerosol generating systems are portable, electrically operated, and typically include a rechargeable battery to provide the necessary power. It is important that the batteries in the aerosol generating system are charged in a safe manner, otherwise the batteries may become unstable and lead to catastrophic failure of the aerosol generating device. This is particularly important for aerosol generating systems, as these systems typically generate heat and are used in close proximity to the user's body.

[0003] One safety feature commonly used in controllers that charge batteries is the so-called "safety timer." This safety feature involves timing the period during which the battery has been charged and terminating charging if the battery is still charging after a predetermined period of time.

[0004] A problem with conventional "safety timer" features is that the system (e.g., the battery) may be faulty at the start of a charge cycle, but the safety timer may allow the charge controller to charge the battery until the end of a predetermined period. The predetermined period at which charging is terminated may be fixed, for example, to a maximum of 10 hours. Thus, if the battery is defective at the start of a charge cycle, the battery may be allowed to continue charging for 10 hours, which may lead to catastrophic failure of the aerosol generating device.

[0005] It would therefore be desirable to provide more sophisticated charging safety features that can help avoid catastrophic failures while charging batteries in aerosol generating systems.

[0006] It would further be desirable to provide a charging method that could help detect charging problems at an early stage during the charging process. Summary of the Invention

[0007] According to an embodiment of the present invention, there is provided a method for charging a battery in an aerosol generating system, the method comprising: - initiating charging of a battery; - monitoring an electrical parameter indicative of the charging rate of the battery; - determining the charging rate of a battery; - comparing the determined charging rate with a reference charging rate; - inhibiting the battery from being charged if the charging rate deviates from a reference charging rate.

[0008] According to one embodiment of the present invention, there is provided a method for charging a battery in an aerosol generating system, the method comprising: - initiating charging of a battery; - monitoring an electrical parameter indicative of the charging rate of the battery; - determining the charge rate of the battery by monitoring changes in an electrical parameter over a given period of time; - comparing the determined charging rate with a reference charging rate, the reference charging rate being defined by a change in the monitored electrical parameter; - inhibiting the battery from being charged if the charging rate deviates from a reference charging rate.

[0009] By determining the charging rate during the charging process, anomalous charging can be detected early. Thus, with the method of the present invention, the charging process can be interrupted, stopped completely, or reduced to a safe level upon detection of an unsafe charging rate. In this way, the present invention makes it possible to avoid prolonged charging of defective batteries. Thereby, the present invention helps to reduce potentially dangerous situations associated with charging batteries used in aerosol generating systems.

[0010] For example, the power source may be a nickel metal hydride battery, a nickel cadmium battery, or a lithium ion battery, such as lithium cobalt oxide (LCO), lithium iron phosphate (LFP), lithium nickel manganese cobalt (NMC), lithium nickel manganese cobalt oxide (NMC), lithium nickel cobalt aluminum oxide (NCA), or a lithium polymer battery (LiPo). The power source may require recharging and may have a capacity that allows it to store sufficient energy for one or more use experiences, for example, the power source may have a capacity sufficient to continuously generate aerosol for about 4-10 minutes, or about 6 minutes, or a multiple of about 4-10 minutes, or a multiple of about 6 minutes. In another embodiment, the power source may have a capacity sufficient to provide a predetermined number of puffs, or discontinuous activation of the heating element.

[0011] The reference charge rate may be an expected charge rate. A charging process for charging a rechargeable battery may include different charging modes. The charging modes may differ in the way power is delivered to the battery.

[0012] In an embodiment, the charging modes of the charging process may include a pre-charge mode, a current regulation mode, and a voltage regulation mode.

[0013] In the pre-charge mode, a first constant current (e.g., referred to as a "pre-charge current") may be applied until the voltage output of the battery reaches a pre-charge voltage threshold.

[0014] In the constant current regulation mode, a second constant current (e.g., referred to as the "regulation current") may be applied. The regulation current applied in the constant current mode may be greater than the pre-charge current applied in the pre-charge mode. The regulation current may be applied until the voltage output of the battery reaches the regulation voltage threshold. Thus, the constant current regulation mode may be used whenever the voltage output of the battery is within the range between the pre-charge voltage threshold and the regulation voltage threshold.

[0015] After the pre-charge and constant current regulation modes are completed, a constant voltage regulation mode may be used. In this mode, a constant voltage (e.g., referred to as a "regulation voltage") may be applied to the battery while the charging current is continuously decreased. The regulation voltage may be applied until the charging current drops to the end-of-charge current level. When the charging current reaches the end-of-charge current level, this indicates that the battery has reached its desired state of charge. Once this desired state of charge is reached, the battery may be considered fully charged and charging may be stopped.

[0016] The one or more parameters indicative of the charge rate of the battery that are monitored and the reference charge rate may be selected depending on the charging mode applied. The one or more parameters indicative of the charge rate may be the output voltage of the battery and / or the current drawn by the battery during charging. The charge rate may be determined from the monitored electrical parameters.

[0017] In charging modes where a constant current is applied, i.e. in the pre-charge and constant current regulation modes, the parameter indicative of the charging rate may be the output voltage of the battery being charged. Over a wide range of these charging modes, the output voltage of the battery generally increases linearly over time. The increase in the output voltage tapers off towards the end of the constant current regulation mode when the output voltage approaches the regulation voltage threshold.

[0018] In the voltage regulation mode, a constant voltage is applied. In this charging mode, the parameter indicative of the charging rate may be the current drawn by the battery being charged. In the voltage regulation mode, the current drawn may decrease exponentially over time.

[0019] The charge rate may be determined by any suitable method known to one of skill in the art. To determine the charge rate, an electrical parameter indicative of the charge rate of the battery may be monitored. In an embodiment, the charge rate of the battery may be obtained by monitoring the change in the electrical parameter over a given period of time. In one illustrative example, the change in the electrical parameter may be zero, in other words, monitoring the change in the electrical parameter may include observing that no change in the electrical parameter occurs. This may indicate a fault, and thus charging may be appropriately inhibited. Monitoring the electrical parameter may include determining the electrical parameter at a first time and determining the electrical parameter at a second time. In one example, the parameter indicative of the charge rate is the power or energy supplied to the battery during charging, or the state of charge of the battery. The power or energy supplied to the battery during charging may be monitored over time, and thus the charge rate of the battery may be determined. A high power or energy supplied to the battery over a time interval indicates a high charge rate, and a low power or energy supplied to the battery over a time interval indicates a low charge rate. Additionally or alternatively, the state of charge of the battery may be monitored over time, and thus the charge rate may be determined. A faster increase in the battery's state of charge over the hourly interval indicates a higher charge rate, while a slower increase in the battery's state of charge over the hourly interval indicates a lower charge rate.

[0020] The difference in the values ​​of the electrical parameter determined at the two times may be divided by the time difference between the two different times, and the resulting ratio of the difference in the two values ​​of the electrical parameter and the time difference may be indicative of the currently applied charging rate.

[0021] The electrical parameter may be monitored at regular time intervals. The time intervals may be adapted to the type of battery being charged. The time intervals may be adapted to the type of power source used to charge the battery. The time intervals may be adapted to a predefined charging scheme applied to charge the battery.

[0022] The electrical parameter may be monitored every second. The electrical parameter may be monitored every 10 seconds. The electrical parameter may be monitored every 20 seconds. The electrical parameter may be monitored every minute, every 5 minutes, every 10 minutes, every 30 minutes, every hour, or every 2 hours. The time interval between each monitoring of the electrical parameter is preferably less than the expected maximum time the battery should be charged.

[0023] The method may include determining the charge rate by monitoring the state of charge of the battery, by monitoring the output voltage of the battery, or by monitoring a charging current applied to charge the battery.

[0024] The method may include determining the charge rate by monitoring a number of electrical parameters indicative of the charge rate of the battery.

[0025] The method may include determining the charge rate by monitoring the state of charge of the battery and the output voltage of the battery. The method may include determining the charge rate by monitoring the state of charge of the battery and the charging current applied to charge the battery. The method may include determining the charge rate by monitoring the output voltage of the battery and the charging current applied to charge the battery. The method may include determining the charge rate by monitoring the state of charge of the battery, the output voltage of the battery, and the charging current applied to charge the battery. Which or which combination of parameters indicative of the charging rate of the battery are used at a given time may be selected depending on the current charging mode applied.

[0026] The charging rate of the battery may be determined by monitoring the change in the electrical parameter over a given period of time. Monitoring the electrical parameter may include determining the electrical parameter at a first time and determining the electrical parameter at a second time. The difference in the values ​​of the electrical parameter determined at the two times may be divided by the time difference between the two different times. The resulting ratio of the difference between the two values ​​of the electrical parameter and the time difference may be indicative of the currently applied charging rate. If the parameter is monitored at regular intervals, the difference between successively determined values ​​of the electrical parameter may be used as a measure of the charging rate.

[0027] The expected change in the monitored electrical parameter may depend on the duration of the measurement interval: the shorter the interval, the smaller the expected change in the monitored electrical parameter.

[0028] The currently applied charging rate determined as described above may then be compared to a reference charging rate. The reference charging rate may be determined from a charging scheme stored in a data storage unit of the aerosol generating system. The reference charging rate may be determined from an average of previous charging processes. The previous charging processes may be used to modify the stored standard charging scheme. By taking into account the previous charging processes for a given battery, the reference charging rate may be customized to better approximate the charging process for the given battery.

[0029] The reference charge rate may be defined by a change in the monitored electrical parameter. For example, the reference charge rate may be defined by a change in the voltage output of the battery, or the reference charge rate may be defined by a change in the current applied to charge the battery. The actual charge rate of the battery may then be determined by measuring the electrical parameter (e.g., the voltage output of the battery, or the current applied to charge the battery) at two or more time points and calculating the change in the electrical parameter. If the calculated change in the measured electrical parameter deviates from the change in the electrical parameter defined by the reference charge rate, charging may be inhibited. For example, if the calculated change in the measured electrical parameter is lower than the change in the electrical parameter defined by the reference charge rate, this may indicate a fault in the charging system. Thus, charging may be inhibited or prevented. In one illustrative example, there may be no change in the observed electrical parameter, and the reference charge rate may be defined as a non-zero change in the electrical parameter. In this case, the change in the electrical parameter will be less than the reference charge rate, and therefore charging may be inhibited accordingly.

[0030] The reference charge rate may be defined by mathematical means: the reference charge rate may be defined by a linear or non-linear relationship between parameters indicative of charge rate and time.

[0031] For example, during the pre-charge mode, a relatively linear relationship between battery voltage and charge time is expected. Thus, the following linear equation may be used to define the relationship between battery voltage and charge time: (1) V b (t)=mt+c In the formula, V b is the battery output voltage, t is time, and m and c are coefficients. The value of "m" may depend on system parameters such as the current drawn by the battery and the temperature of the battery.

[0032] In contrast, in voltage regulation mode, the relationship between charging current and time may be better approximated by a nonlinear equation. In particular, in voltage regulation mode, the charging current may be considered to decay exponentially over time. Therefore, it may be more appropriate to estimate the charging current with the following exponential formula: (2)I C (t)=e -mt In the formula, I C is the charging current, t is the time, and m is a coefficient.

[0033] In the precharge mode, determining the reference charge rate may include the following steps.

[0034] In a first step, the output voltage of the battery may be determined. In a further step, the voltage difference (dV) between a pre-defined pre-charge threshold and the output voltage is determined. In a next step, a reference time (dT) is determined, which is expected to be required to charge the battery from the output voltage to the pre-charge threshold voltage. The expected time to reach the pre-charge threshold may be determined by assuming a standard charging process carried out under a standard operating environment. Such information may be obtained in a separate calibration step of sample batteries during manufacturing. The reference charging rate may then be calculated by dividing dV by dT.

[0035] In a constant current charging mode, the determination of the reference charge rate may be performed in a similar manner.

[0036] Again in a first step the output voltage of the battery may be determined. In a further step the voltage difference (dV) between a predefined regulation voltage threshold and the output voltage is determined. In a next step a reference time (dT) is determined that is expected to be required to charge the battery from the output voltage to the regulation voltage threshold. The reference charge rate may then again be calculated by dividing dV by dT.

[0037] The reference time dT may depend on the current applied to charge the battery. For example, if the current applied to charge the battery is high, the expected charging time will be shorter and therefore the reference time dT will be shorter. On the other hand, if the current applied to charge the battery is smaller, the expected charging time will be longer and therefore the reference time dT will be longer.

[0038] In a voltage regulated charging mode, determining the reference charge rate may include the following steps.

[0039] In the first step, the charging current (I RC ) can be determined. In a further step, the charging current (I RC ) and the end current (I TC ) can be determined. In the next step, a reference time (dT) is determined, which is the difference (dI) between the charging current (I RC ) is the end current (I TC It is expected that the battery needs to be charged until dI equals dT. The reference charge rate can then be calculated by dividing dI by dT.

[0040] The reference time dT may depend on the available current applied to charge the battery, e.g., the current available from a main power source (e.g., USB) or from a battery pack used to charge the battery. For example, if the current available to charge the battery is high, the expected charging time will be shorter and therefore the reference time dT will be shorter. On the other hand, if the current available to charge the battery is low, the expected charging time will be longer and therefore the reference time dT will be longer.

[0041] If the charge rate deviates from the reference charge rate by at least a predetermined deviation, charging of the battery may be inhibited. The amount of the predetermined deviation may be defined taking into account the circumstances of how the charge rate is determined. In particular, it may take into account how accurately the charge rate is determined and what typical, and therefore acceptable, variations in the charge rate are expected. The amount of the predetermined deviation may be selected based on the operating environment, for example based on temperature readings from a temperature sensor. The predetermined deviation from the reference charge rate may correspond to a maximum of 40 percent of the reference charge rate. The predetermined deviation from the reference charge rate may correspond to a maximum of 25 percent of the reference charge rate. The predetermined deviation from the reference charge rate may correspond to a maximum of 10 percent of the reference charge rate.

[0042] The reference charge rate may be defined as a range of charge rates between a lower charge rate threshold and / or an upper charge rate threshold. The lower charge rate threshold and / or the upper charge rate threshold may be suitably selected for any given battery and power source available for charging. A too narrow range may increase the sensitivity of the charge controller, but may also increase the risk that an otherwise acceptable change in charge rate will falsely trigger a stop of the charging process. An overly broadly defined range of charge rates may reduce the sensitivity of the charge controller and delay the recognition of a faulty charging process.

[0043] In defining the acceptable range of charging rates, a lower charging rate threshold and / or an upper charging rate threshold may be determined by multiplying the determined reference charging rate by a scaling factor. The scaling factor for determining the lower charging rate threshold may be defined by (1-X), where X may correspond to a maximum of 0.9, X may correspond to a maximum of 0.8, X may correspond to a maximum of 0.6, X may correspond to a maximum of 0.4, X may correspond to a maximum of 0.2, or X may correspond to a maximum of 0.1.

[0044] The scaling factor for determining the upper charge rate threshold may be defined by (1+X), where X may correspond to a maximum of 0.9, X may correspond to a maximum of 0.8, X may correspond to a maximum of 0.6, X may correspond to an amount of a maximum of 0.4, X may correspond to a maximum of 0.2, or X may correspond to a maximum of 0.1.

[0045] The parameter X for determining the scaling factor for the lower charge rate threshold may be the same as the parameter X used to determine the upper charge rate threshold. In cases where there is a linear relationship between the monitored parameter and time, it may be advantageous to use symmetric definitions of the lower and upper charge rate thresholds. In contrast, for non-linear relationships between the monitored parameter and time, it may be advantageous to use asymmetric definitions of the lower and upper charge rate thresholds.

[0046] In some embodiments, it may be sufficient to define only a lower charge rate threshold or only an upper charge rate threshold: in either case, charging that is too slow or too fast may be determined and used to identify a faulty charging process.

[0047] In embodiments where the reference charge rate is defined by a linear or nonlinear equation, the monitored electrical parameter may be continuously recorded over time. The recorded values ​​may then be approximated by calculating an approximation equation. For example, in the case of an expected linear relationship between the monitored parameter and time according to equation (1) above, the monitored relationship between battery voltage and time may be calculated to be best approximated by the following equation: (3) V b (t) = m1 t + c1

[0048] These two functions can then be compared to one another to calculate a value that defines the similarity between the two functions. One way to define the similarity between two functions is to perform a cross-correlation between the two functions. The smaller the magnitude of the output of the cross-correlation, the higher the similarity between the recorded charging rate and the reference charging rate. If the measured difference between the recorded charging rate and the reference charging rate exceeds a threshold, this may indicate a fault in the system and charging can be appropriately throttled.

[0049] Defining an upper charge rate threshold and a lower charge rate threshold may be a simple and effective mechanism for determining the range of acceptable charge rates during charging. This method is particularly effective for charge modes where little change in charge rate is expected. However, if the relationship between the monitored electrical parameter and time is non-linear, larger changes in charge rate are expected throughout a given charge mode. This means that the upper and lower charge rate thresholds need to be set accordingly, taking into account the highest and lowest charge rates that may be encountered.

[0050] To further increase the sensitivity of the method, one or more of the charging modes may be subdivided into multiple charging segments. The reference charging rate and upper and lower charging thresholds may be different for each segment of each charging mode. For example, a given charging mode may be subdivided into two, three, four, or even more charging segments. The idea here is to subdivide a non-linear charging mode into multiple segments, each of which more closely follows a linear relationship.

[0051] It may be particularly advantageous to subdivide a charging mode in which the current regulation mode is applied to two or more segments. A first segment may be defined in which a constant and rather fast charging rate is expected. A second segment may be defined to encompass the non-linear part of this charging mode. In this way, a higher upper charge rate threshold may be applied to the first segment compared to the upper charge rate threshold used in the second segment. Also, a higher lower charge rate threshold may be applied to the first segment compared to the lower charge rate threshold in the second segment. If only a pair of charge rate thresholds is selected for this charging mode, the lower charge rate threshold for the second segment and the upper charge rate threshold for the first segment could have been selected for the complete charging mode. This results in a wide range of acceptable charging rates, which will detect a defective charging process and extend the time to later termination of the charging process. Instead, by subdividing the mode into multiple segments, the sensitivity of the method is enhanced and defective charging processes can be detected at an early stage.

[0052] It may be possible that the breach of one of the charging thresholds may be an irregular breach. In such a case, it would not be necessary or desirable to stop the charging process. Therefore, multiple breaches of any of the charging thresholds may be required to avoid premature termination of the charging process. Therefore, only repeated breaches of any of the charging thresholds will trigger the termination of the charging process. The number of breaches required may be freely selected depending on the circumstances of the respective aerosol generating system. The number of detected breaches that will trigger the termination of the charging process may be, for example, 5, 10 or 15 breaches. Also, the breaches may be required to be consecutive or non-consecutive breaches. It may also be possible to define the trigger thresholds using a mixture of consecutive and non-consecutive breaches. For example, charging may be stopped if 5 consecutive breaches or 10 non-consecutive violations are determined.

[0053] According to one embodiment of the present invention, an aerosol generating system is provided, comprising a battery and a charge controller. The aerosol generating system is configured to perform the charging method as described above. To this end, the charge controller is configured to initiate charging of the battery and to monitor an electrical parameter indicative of a charging rate of the battery. The charge controller is further configured to determine a charging rate of the battery and to compare the determined charging rate with a reference charging rate. If the charging rate deviates from the reference charging rate, the charge controller is configured to inhibit the battery from being charged.

[0054] The charge controller may be configured to determine a charge rate of the battery by monitoring changes in an electrical parameter over a given period of time and to compare the determined charge rate to a reference charge rate, the reference charge rate being defined by the changes in the monitored electrical parameter, and to inhibit the battery from being charged if the charge rate deviates from the reference charge rate.

[0055] The aerosol generation system may comprise an aerosol generation device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol generation system may further comprise a charging case. The charging case may be a portable charging case. The charging case may be configured to be connected to the aerosol generation device for charging purposes.

[0056] The term "aerosol-generating device" as used herein refers to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol-generating device may interact with one or both of an aerosol-generating article that includes an aerosol-forming substrate and a cartridge that includes an aerosol-forming substrate. In some examples, the aerosol-generating device may heat the aerosol-forming substrate to facilitate the release of volatile compounds from the substrate. An electrically operated aerosol-generating device may include an atomizer, such as an electric heater, for heating the aerosol-forming substrate to form an aerosol.

[0057] According to one embodiment of the present invention, there is provided an aerosol generating device for use in an aerosol generating system. The aerosol generating device comprises a rechargeable battery, a first power interface for connecting the rechargeable battery to an external power source, and a host controller for controlling the power supply from the rechargeable battery to the electric heater. The aerosol generating device further comprises a charge controller. The charge controller may be included in the host controller of the aerosol generating device. Alternatively, the charge controller may be included in the battery charger IC of the aerosol generating device.

[0058] Providing a charging controller within the aerosol generating device increases the versatility of the aerosol generating device for charging. In these embodiments, the charging process may be controlled by circuitry provided within the aerosol generating device. To carry out the charging process, it is sufficient to connect the aerosol generating device to a suitable external power source.

[0059] The external power supply may be a mains AC adapter that receives AC input from a mains power source and outputs a DC voltage suitable for charging a rechargeable battery. Typically, a DC output of about 5 volts is provided by the power supply.

[0060] The first power interface for connecting to a power source may be any suitable connection means. The connection means may be a USB interface, such as a USB-A or USB-C interface.

[0061] The aerosol generating device may further comprise a host microcontroller. The host microcontroller may be configured to perform the necessary functions of the aerosol generating device, such as providing power from a battery to a heater so that an aerosol can be generated from the aerosol generating substrate. The host microcontroller may further be configured to comprise a charge controller. Thus, the host microcontroller may also be configured to perform and control the charging process of the rechargeable battery of the aerosol generating device.

[0062] The aerosol generating device may also comprise a separate battery charger IC. If provided, the battery charger IC may be configured to perform and control the charging process of the rechargeable battery of the aerosol generating device.

[0063] A rechargeable battery in the aerosol generator provides power to the host microcontroller and heater so that the aerosol generator can be used when not connected to a power source.

[0064] According to an embodiment of the present invention, there is provided a charging case for an aerosol generating device as described above. The charging case may comprise a rechargeable battery and a first power interface for connecting the rechargeable battery of the charging case to an external power source. The charging case may comprise a second power interface for connecting the rechargeable battery of the charging case to the rechargeable battery of the aerosol generating device. The charging case may further comprise a charging controller for charging the rechargeable battery of the aerosol generating device.

[0065] By providing a charging controller in the charging case, there is no need to provide a charging controller in the aerosol generating device. Therefore, less electronic circuitry is required in the aerosol generating device. This can reduce the complexity of manufacturing the aerosol generating device. At the same time, the cost efficiency of the manufacturing process of the aerosol generating device can be increased.

[0066] Furthermore, the external power source may be a mains AC adapter that receives an AC input from a mains power source and outputs a DC voltage. The first power interface for connecting the charging case to the power source may be any suitable connection means. The connection means may be a USB interface, such as a USB-A or USB-C interface.

[0067] The second power source for connecting the rechargeable battery of the charging case to the rechargeable battery of the aerosol generating device may also be any suitable connection means, and may even be a USB interface.

[0068] According to one embodiment of the present invention, there is provided a charging case for an aerosol generating device as described above. The charging case may comprise a rechargeable battery and a first power interface for connecting the rechargeable battery of the charging case to an external power source. The charging case may comprise a second power interface for connecting the rechargeable battery of the charging case to the rechargeable battery of the aerosol generating device. The charging case may further comprise a host microcontroller comprising a charge controller for charging the rechargeable battery of the charging case. Alternatively, the charging case may comprise a battery charger IC comprising a charge controller for charging the rechargeable battery of the charging case.

[0069] The host microcontroller of the charging case may be configured to perform the necessary functions of the charging case. Such functions may include downloading data from the aerosol generating device. The host microcontroller may also be configured to communicate with an external device, such as a computer. The host microcontroller may also be configured to perform the transmission of downloaded data from the aerosol generating device to an external device, such as a computer, via a USB interface. EXAMPLES

[0070] The present invention is defined in the claims. However, below is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of the other examples, embodiments, or aspects described herein.

[0071] Example A: 1. A method for charging a battery in an aerosol generating system, comprising: - initiating charging of a battery; - monitoring an electrical parameter indicative of the charging rate of the battery; - determining the charging rate of the battery; - comparing the determined charging rate with a reference charging rate; - inhibiting the battery from being charged if the charge rate deviates from the reference charge rate. Example A': 1. A method for charging a battery in an aerosol generating system, the method comprising: - initiating charging of a battery; - monitoring an electrical parameter indicative of the charging rate of the battery; - determining the charge rate of the battery by monitoring changes in an electrical parameter over a given period of time; - comparing the determined charging rate with a reference charging rate, the reference charging rate being defined by a change in the monitored electrical parameter; and inhibiting the battery from being charged if the charge rate deviates from a reference charge rate. Example B: The method of embodiment A or embodiment A', wherein a plurality of parameters indicative of the charging rate of the battery are monitored. Example C: The method of embodiment A or embodiment A', wherein the parameters indicative of the charge rate are the battery's state of charge and the battery's output voltage. Example D: The method of embodiment A or embodiment A', wherein the parameters indicative of the charge rate are the state of charge of the battery and the charging current applied to the battery. Example E: The method of any of embodiments AD, wherein the reference charge rate is an expected charge rate. Example F: The method of any of embodiments A-E, wherein the battery is a rechargeable lithium ion battery. Example G: The method of any of embodiments A-F, wherein charging of the battery is inhibited if the charge rate deviates from the reference charge rate by at least a predetermined deviation. Example H: The method of any of embodiments A-G, wherein the charging process includes different charging modes. Example I: The method of any of embodiments A-H, wherein the charging process includes a pre-charge mode, a current regulation mode, and a voltage regulation mode. Example J: The method according to any of embodiments AI, wherein the parameter indicative of the charging rate of the monitored battery is selected depending on the charging mode applied. Example K: The method according to any of the embodiments A to J, wherein the parameter indicative of the charging rate is the output voltage of the battery, the current applied to the battery, the energy supplied to the battery, the power supplied to the battery, or the state of charge of the battery. Example L: The method of any of embodiments A-K, wherein monitoring the electrical parameter comprises determining the electrical parameter at a first time and determining the electrical parameter at a second time. Example M: The method of example L, wherein determining a charge rate of the battery includes calculating a ratio of a change in the electrical parameter determined at the first time and the second time and a time difference between the first time and the second time. Example N: The method of any of embodiments A-M, wherein the reference charging rate is determined from a charging scheme stored in a data storage unit of the aerosol generating system. Example O: The method of any of embodiments A-N, wherein the reference charge rate is defined as a change in the monitored electrical parameter. Example P: The method of any of embodiments A-O, wherein determining the charge rate comprises monitoring a change in an electrical parameter between a first time and a second time. Example Q: The method of any one of examples O and P, wherein the method further includes determining that the charge rate deviates from a reference charge rate by determining that the monitored change in the electrical parameter is less than a change in the monitored electrical parameter defined by a reference charge rate. Example R: determining a reference charge rate in the pre-charge mode and / or the current regulation charge mode, determining an output voltage of a battery; determining, for each charging mode, a difference dV between the output voltage and a predetermined threshold voltage; determining a reference time dT for charging the battery from the output voltage to a threshold voltage; The method of any of embodiments A-Q, comprising: calculating a reference charge rate by dividing dV by dT. Example S: The method of embodiment R, wherein the reference time dT is dependent on the current applied to charge the battery. Example T: In a voltage regulation charging mode, determining a reference charge rate comprises: determining a charging current IRC to a battery; determining a difference dI between the charging current IRC and the termination current ITC; determining a reference time dT for charging the battery until the charging current is equal to the termination current; and calculating a reference charge rate by dividing dI by dT. Example U: The method of embodiment T, wherein the reference time dT is dependent on the current available to charge the battery. Example V: The method of any of embodiments A-U, wherein the reference charge rate is defined as a range of charge rates between a lower charge rate threshold and / or an upper charge rate threshold. Example W: The method of embodiment V, wherein the lower charge rate threshold and the upper charge rate threshold are determined from multiplying the determined reference charge rate by a scaling factor. Example X: The method of example W, wherein a scaling factor for determining the lower charge rate threshold is defined as (1−X), and a scaling factor for determining the upper charge rate threshold is defined as (1+X), where X may correspond to up to 0.9, X may correspond to up to 0.8, X may correspond to up to 0.6, X may correspond to up to 0.4, X may correspond to up to 0.2, or X may correspond to up to 0.1. Example Y: The method of example X, wherein the parameter X for determining the scaling factor for the lower charge rate threshold and the upper charge rate threshold is the same. Example Z: The method of any of embodiments A-Y, wherein the charging mode is divided into a plurality of segments, and the reference charging rate and upper and lower charging thresholds are different for each segment of each charging mode. Example ZA: The method of any of embodiments A-Z, wherein the reference charge rate is defined by a linear or non-linear relationship between parameters indicative of charge rate and time. Example ZB: The method of example ZA, wherein continuously monitored values ​​of an electrical parameter indicative of a charge rate of the battery are recorded and these recorded values ​​are compared to a reference charge rate according to a linear or nonlinear relationship between the parameter indicative of the charge rate and time. Example ZC: The method of any of embodiments A-ZB, wherein charging is inhibited only after the charge rate is found to deviate from the reference charge rate at least a predetermined number of times. Example ZD: The method of example ZC, wherein charging is inhibited only after the charge rate is found to deviate from the reference charge rate at least 5 times, at least 10 times, or at least 15 times. Example ZE: 1. A charge controller for an aerosol generating system, the charge controller comprising: Start charging the battery, monitoring an electrical parameter indicative of the rate at which the battery is being charged; Determine the charging rate of the battery, Comparing the determined charging rate to a reference charging rate; The charge controller is configured to inhibit the battery from being charged if the charge rate deviates from a reference charge rate by at least a predetermined deviation. Example ZE': 1. A charge controller for an aerosol generating system, the charge controller comprising: Start charging the battery, monitoring an electrical parameter indicative of the rate at which the battery is being charged; Determining the charge rate of the battery by monitoring changes in an electrical parameter over a given period of time; comparing the determined charge rate to a reference charge rate, the reference charge rate being defined by a change in the monitored electrical parameter; The charge controller is configured to inhibit the battery from being charged if the charge rate deviates from a reference charge rate by at least a predetermined deviation. Example ZF: An aerosol generating device comprising: a rechargeable battery; a first power interface for connecting the rechargeable battery to an external power source; and a host controller for controlling a power supply from the rechargeable battery to an electric heater, The host controller comprises a charge controller of embodiment ZE or embodiment ZE' for charging the rechargeable battery; or An aerosol generating device comprising a battery charger IC having a charge controller of embodiment ZE or embodiment ZE' for charging a rechargeable battery. Example ZG: A charging case for an aerosol generating device, the charging case comprising: a rechargeable battery; a first power interface for connecting the rechargeable battery of the charging case to an external power source; and a second power interface for connecting the rechargeable battery of the charging case to the rechargeable battery of the aerosol generating device, The charging case further comprises a charging controller of embodiment ZE or embodiment ZE' for charging a rechargeable battery of the aerosol generating device. Example ZH: A charging case for an aerosol generating device, the charging case comprising: a rechargeable battery; a first power interface for connecting the rechargeable battery of the charging case to an external power source; and a second power interface for connecting the rechargeable battery of the charging case to the rechargeable battery of the aerosol generating device, The charging case further comprises a host microcontroller comprising a charging controller of embodiment ZE or embodiment ZE' for charging the rechargeable battery of the charging case; or A charging case comprising a battery charger IC having a charge controller of embodiment ZE or embodiment ZE' for charging a rechargeable battery of the charging case.

[0072] Features described with respect to one embodiment may be equally applied to other embodiments.

[0073] The embodiments will now be further described with reference to the accompanying drawings. [Brief description of the drawings]

[0074] [Figure 1] FIG. 1 shows a typical prior art charging process. [Diagram 2] FIG. 2 shows the first stage of the charging method. [Diagram 3] FIG. 3 shows the second stage of the charging method. [Figure 4] FIG. 4 illustrates the determination of the allowable charge rate range in constant current regulation mode. [Diagram 5] FIG. 5 illustrates the determination of the allowable charge rate range in the constant voltage regulation mode. [Figure 6] FIG. 6 illustrates the timing advantage of the method. [Figure 7] FIG. 7 shows a modification of the charging method. [Figure 8] FIG. 8 shows the configuration of an aerosol generation system. [Figure 9] FIG. 9 shows an aerosol generation system including a charging case. [Figure 10] FIG. 10 shows a modification of the aerosol generation system of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0075] In Figure 1, a typical charging process 10 for a lithium-ion battery is illustrated. The charging process essentially includes three different charging modes, called pre-charge mode 20, constant current regulation mode 22, and constant voltage regulation mode 24. In the final stage, called end charge 26 in Figure 1, charging of the rechargeable battery is terminated.

[0076] 1, charging current 30 is plotted as a dark grey line and battery voltage 32 is plotted as a light grey solid line. Assuming a charging process 10 for a slightly depleted battery, the charging process 10 begins in a pre-charge mode 20.

[0077] In precharge mode 20, the "precharge current" (I PC ), 34. A first constant current, called the precharge current (I PC ) may be about 5 mA or more. In one example, the pre-charge current (I PC ) may be about 10% of the current applied in the constant current regulation mode. This precharge current 34 occurs when the battery voltage 32 is below the precharge voltage threshold (V PC )36 is applied until the precharge voltage threshold (V PC ) may be about 2V to 4V, about 2.5V to 3V, about 3V, or about 2V or less.

[0078] In the following charging modes, the constant current regulation mode 22, "regulation current" (I RC ), a second constant current, referred to as 38, is applied. RC) may be about 50mA to 4A. In this charging mode, the battery voltage 32 initially increases approximately linearly. When the battery voltage 32 increases to the regulation voltage (V Reg ) 40, the increase in the battery voltage 32 slows down. The regulated voltage may be about 3V-4.5V. In particular, the regulated voltage may be about 3.6V-3.7V and the battery includes lithium iron phosphate. The regulated voltage may be about 4V-4.5V and the battery includes lithium cobalt oxide (LCO), lithium nickel manganese cobalt oxide (NMC), or lithium nickel cobalt aluminum oxide (NCA).

[0079] Adjustment voltage (V Reg ) 40, the constant voltage regulation mode 24 is used. In this mode, the regulation voltage (V Reg A constant voltage corresponding to the regulated voltage (V) 40 is applied to the battery while the charging current 30 is continuously decreased. Reg ) 40 is the charge current 30 and the charge termination current (I TC ) 42. In the graph of FIG. 1, the charge termination current (I TC The level of the precharge current (I PC ) 34. However, the charge termination current (I TC ) 42 is the precharge current (I PC ) 34 or the charge termination current (I TC ) 42 is the precharge current (I PC )34 may be greater.

[0080] Charging current 30 is the charging end current (I TC ) 42, the battery is considered to have reached its desired state of charge and charging is stopped.

[0081] The prior art charging process 10 shown in FIG. 1 typically lasts for hours or minutes. In conventional charging systems, a timing safety feature is used. According to this safety feature, charging is terminated after a predefined time, independent of the battery's state of charge. Thereby, a defective battery that can never reach its desired state of charge (SoC) is prevented from being continuously charged. This safety feature reduces the risk of catastrophic failure during charging.

[0082] The charging method aims to identify charging problems already at an early stage and to terminate charging if such a problem is detected.

[0083] The method is illustrated by the flow charts in Figures 2 and 3. The method is implemented in an aerosol generating system that includes a host microcontroller and a battery charging IC. A first step 50 of the method is shown in the flow chart of Figure 2. In this step, the charge controller determines which charging mode is to be applied. After initiating the charging process 52, the charge controller determines the battery output voltage (V b ) to determine

[0084] Output voltage (V b ) is the precharge threshold voltage (V PC ), precharge mode is entered at step 56.

[0085] Output voltage (V b ) is the precharge threshold voltage (V PC ) but the regulation voltage (V REG ), then constant current regulation mode is entered at step 58.

[0086] Output voltage (V b ) is the regulated voltage V REG If it does match or is greater than , then in step 59 , a voltage and current regulation mode is entered .

[0087] Once the charging mode selection in the first phase 50 is complete, the charging process continues in a second phase 60, as shown in Figure 3. In the second phase 60, the battery charger IC communicates the selected charging mode to the host microcontroller (step 62). The host microcontroller then selects a nominal (or "expected") charging rate based on the determined charging mode, as shown in step 64 of the flowchart in Figure 3.

[0088] 2 and 3, for each charging mode, upper and lower charge rate thresholds are stored in the host microcontroller's memory. In step 64, these stored charge thresholds for the selected charging mode are read from the host microcontroller's memory. Thus, in this example, the expected charge rate is defined as a range of charge rates.

[0089] After the host microcontroller selects an expected charge rate for a given charging mode, the host microcontroller monitors the rate at which the battery is being charged at regular sampling intervals. This is done by monitoring an electrical parameter indicative of the charge rate. Depending on the charging mode, this parameter may be the change in battery voltage or the amplitude of the change in charging current over a sampling time. Each monitored electrical parameter is measured at a first time in method step 66. After pausing for the sampling time (step 68), the monitored electrical parameter is measured at a second time in method step 70. After verification that the monitored electrical parameter is still consistent with the selected charging mode (step 72), the charge rate is calculated based on these two measurements for the electrical parameter in step 74. The charge rate is calculated as the ratio of the difference between the two values ​​of the electrical parameter measured at the first and second times and the sample time dT between these two measurements.

[0090] In the example of FIGS. 2 and 3, upper and lower thresholds define the expected charging rate, and charging is terminated in method step 76 if the amplitude of the change breaches either the upper or lower threshold.

[0091] If the determined charging rate is within the expected charging range, charging is allowed to continue. To this end, the method continues at step 66 by again determining the charging rate.

[0092] In one example, expected rates of charge and sample times (Ts) may be predefined and stored in memory, each associated with a particular charging mode. For example, the precharge mode may be expected to end after an absolute maximum time of one hour (assuming charging conditions that would result in a slow charging rate, e.g., low charging current, low temperature, and high battery capacity). Additionally, the maximum change in battery output voltage is expected to occur after a precharge voltage threshold (V PC ) minus the lowest reasonable voltage output of the battery, e.g., 3V-2V=1V. Thus, the predetermined expected charging rate stored in memory for the precharge mode may be 1V of increase in the battery output voltage after 1 hour. Thus, the expected charging rate may be defined as the difference in the voltage output of the battery, e.g., 1V, and the sample time (Ts) may be set to 1 hour. Then, if the voltage output of the battery does not increase by a value less than 1V in 1 hour, the controller may detect that there is a problem in the system and may prevent or inhibit charging.

[0093] The constant current regulation mode can be expected to end after an absolute maximum time of 3 hours (again, assuming charging conditions that result in a slow charge rate, e.g., low charge current, low temperature, and high battery capacity). In addition, the maximum change in battery output voltage is the regulation voltage (V Reg ) to the precharge voltage threshold (V PC), e.g., 4.2V-3V=1.2V. Thus, the predetermined expected charging rate stored in memory for the precharge mode may be 1.2V of increase in battery output voltage after 3 hours. Thus, the expected charging rate may be defined as the difference in the voltage output of the battery, e.g., 1.2V, and the sample time (Ts) may be set to 3 hours. Then, if the voltage output of the battery has not increased by a value less than 1.2V in 3 hours, the controller may detect that there is a problem in the system and may prevent or inhibit charging.

[0094] The constant voltage regulation mode may be expected to end after an absolute maximum time of 2 hours (again, assuming charging conditions that result in a slow charge rate, e.g., low available charge current, low temperature, and high battery capacity). In addition, the maximum change in current applied to charge the battery is the regulation current (I RC ) to the precharge current (I PC ), e.g., 2A-0.2A=1.8A. Thus, the predetermined expected charging rate stored in memory for the pre-charge mode may be 1.8A of the decrease in current applied to charge the battery after 2 hours. Thus, the expected charging rate may be defined as the difference in the current applied to charge the battery, e.g., 1.8A, and the sample time (Ts) may be set to 2 hours. Then, if the current applied to charge the battery has not decreased by a value less than 1.8A in 2 hours, the controller may detect that there is a problem in the system and may prevent or inhibit charging.

[0095] In another example, an acceptable range of expected charging rates may also be defined as illustrated in FIGS.

[0096] For constant current regulation mode 22, the upper charge rate threshold (TU CR ) and the lower charge rate threshold (TL CR ) is set in the following way:

[0097] For a given output voltage (V b ), in the first step, for a given battery voltage (V b ) and the adjustment voltage threshold (V (Reg)) The difference between CR ) is determined. The difference (dV CR ) may be very low, for example, when charging is nearing the end of the constant current regulation mode. In this case, the difference (dV CR ) may be about 0.1 V or more. CR ) may be high, for example, when charging is heading towards the beginning of a constant current regulation mode. In this case, the difference (dV CR ) is V REG and V PC The difference between the input and output voltages may be, for example, approximately 2.5V.

[0098] The next step is to calculate the output voltage (V b ) to adjust voltage (V Reg The expected time (dT CR ) is determined. The expected time (dT CR ) may be very low, for example, when charging is nearing the end of the constant current regulation mode. In this case, the difference (dT CR The expected time (dT CR ) may be high, for example, when charging is heading towards the start of a constant current regulation mode. In this case, the expected time (dT CR ) can be about 5 hours. Depending on the rated capacity of the battery, the expected time (dT CR ) differ because a high capacity battery takes more time to charge and a low capacity battery takes less time to charge.

[0099] The expected average charging rate is then calculated as dV CR and dT CR This ratio gives the normal rate of change of battery voltage 32 versus time in current regulation mode 22. The upper charge rate threshold (TU CR ) and the lower charge rate threshold (TL CR ) is dV CR / dTCR are calculated by multiplying the upper and lower charge rate thresholds (TU CR and T.L. CR ) are set to about 0.15. The expected average charge rate and the charge rate thresholds are shown by the dashed and dotted lines in FIG. 4. The dashed line shows the expected average charge rate in the current regulation mode 22. The dotted lines show the upper and lower charge rate thresholds (TU CR , T.L. CR ) are illustrated respectively.

[0100] For the constant voltage regulation mode 24, the upper and lower charge rate thresholds may be set in the following manner.

[0101] In the first step, the charging current is adjusted to the regulated current (I RC ) at which the charging current reaches the end current ICC The expected time (dT VR ) is determined.

[0102] In the next step, I RC and I TC The difference between VR ), given dI VR As mentioned above, I CT I RC Therefore, dI VR is approximately 0.9×I RC For example, I RC If is 2A, dI VR can be 1.8A.

[0103] The expected average charging rate is then dI VR and dT VR It is calculated as the ratio of

[0104] This ratio gives the normal rate of change of charge current versus time in voltage regulation mode. The upper and lower charge rate thresholds for constant voltage regulation mode are dI VR / dT VR x is calculated by multiplying x by scaling factors (1.0+X) and (1.0-X), respectively. In this case, X is the same and is set at approximately 0.15 for both the upper and lower thresholds. These charge thresholds are shown in Figure 5. The dotted line indicates the normal charge rate in voltage regulation mode. The solid line indicates the upper charge rate threshold for voltage regulation mode. The dotted solid line indicates the lower charge rate threshold for voltage regulation mode.

[0105] The scaling factor may be selected to account for the non-linear relationship between charging current and time. In voltage regulation mode, X is the VR can be chosen to be higher than the normal rate of change in the first half of this mode (fastest rate), and Y is VR can be chosen to be lower than the expected rate of change in the latter part of this mode (slowest rate).

[0106] The advantageous effect of the charging method is illustrated by the diagram in FIG.

[0107] The diagram of FIG. 6 illustrates the charging process for a lithium-ion battery, showing the charging current 30 and expected battery voltage 32 throughout the charging process 10.

[0108] In the example of Figure 6, the battery voltage V b0 is measured at a first time T0. Based on this measurement, the charge controller selects the constant current regulation mode 22 and sets a constant charging current I RC Then, the charge controller applies the battery voltage V b1 As can be seen in FIG. 6, the number of times T 1での電池電圧Vb1is well below the expected battery voltage at that time. For this reason, the host microcontroller determines that the charging rate is much lower than expected at time T1. The charge controller interprets this situation as indicating a fault in the system and inhibits further charging of the battery. Thus, a potentially dangerous situation can be detected already during charging and safety measures can be taken.

[0109] The traditional fixed safety timer approach is to keep the battery charged for a period T that exceeds the total expected charging time of the battery. ST After that, it can only infer a fault and terminate charging. ST is much larger than the time T1 at which the method can estimate a fault. Thus, the method is able to estimate a fault and take corrective action more quickly compared to using the conventionally applied fixed safety timer system.

[0110] In figure 7 a method is illustrated that makes it possible to reduce the time taken to estimate the fault especially during a non-linear charging mode. For this purpose, the non-linear charging mode is divided into several segments, whereby each segment more closely follows a linear relationship.

[0111] In the example of FIG. 7, the current regulation mode is decomposed into two segments. The first segment has a higher expected charge rate than the second segment. Therefore, a higher upper charge rate threshold can be applied to the first segment compared to the upper charge rate threshold in the second segment. Also, a higher lower charge rate threshold can be applied to the first segment compared to the lower charge rate threshold in the second segment. If only one pair of charge rate thresholds is selected for the current regulation mode, the lower charge rate threshold for the second segment and the upper charge rate threshold for the first segment can be selected to represent the highest and lowest expected charge rates. However, this will result in a wide band of acceptable charge rates. Therefore, to be identified as an unacceptable charge rate, the charge rate will need to deviate strongly from the average expected charge rate. This will mean that it will take longer for a fault in the charging process to be detected compared to splitting the charging mode into segments as shown in FIG. 7.

[0112] To execute the method, the host microcontroller determines which segment of the mode charging is currently in by measuring the battery voltage or charging current. A threshold value may then be determined based on these parameters, for example, by referencing a voltage / charging current lookup table, each associated with an upper and lower charge rate threshold.

[0113] The same principles may be applied over a complete charging cycle and may also be used in voltage regulation and / or pre-charge modes.

[0114] Three examples of different architectures of an aerosol generation system 100 for implementing the method are shown in Figures 8-10.

[0115] In FIG. 8, an aerosol generating system 100 includes an aerosol generating device 110 that can be connected to an external power source 102 for charging.

[0116] In the illustrated example, the power supply 102 is a mains AC adapter that receives AC input from the mains and outputs 5V DC via a USB-C cable. The aerosol generating device 110 includes a rechargeable lithium ion battery 112 and a battery charger IC 114 that controls the charging of the battery 112. The battery charger IC 114 receives power from a power interface 116 and delivers it to the battery 112 for charging.

[0117] The aerosol generating device 110 further comprises a host microcontroller 118 for carrying out the necessary functions of the aerosol generating device 110, such as providing power from a battery to a heater 120 so as to enable generation of an aerosol from the aerosol-forming substrate.

[0118] The battery 112 provides power to the host microcontroller 118 and the heater 120 so that the aerosol generating device 110 can be used when it is no longer connected to the power source 102 .

[0119] 9, the aerosol generating system 100 further includes a charging case 120. Power from the external power source 102 is used to charge a rechargeable battery 122 in the charging case 120. The battery 122 in the charging case 120 is then used to charge the battery 112 in the aerosol generating device 110. The aerosol generating device 110 has essentially the same structure as the previous example shown in FIG.

[0120] The charging case 120 includes a battery 122 and a battery charger IC 124 that controls charging of the battery 122 in the charging case 120. The battery charger IC 124 receives power from a power interface 126 and delivers it to the battery 122 for charging. The power interface 126 for connecting the power source 102 to the charging case 120 and the power interface 116 for connecting the charging case 120 to the aerosol generating device 110 are identical and both are USB-C type connections.

[0121] The charging case 120 also includes a host microcontroller 128 for performing the necessary functions of the charging case 120, such as downloading data from the aerosol generating device 110 and transmitting this data to an external computer via a USB-C interface.

[0122] The charging case 120 includes a regulator 129 that receives power from the charging case battery 122 and outputs a predetermined voltage of 5V to the aerosol generating device 110. Similar to the example of Fig. 8, the aerosol generating device 110 includes a battery 112 and a battery charger IC 114 that controls charging of the battery 112 in the aerosol generating device 110. The battery charger IC 114 receives power from its power interface 116 and delivers it to the battery 112 for charging.

[0123] In the example of FIG. 10, the aerosol generating system 100 again comprises a charging case 120 and is generally similar to the previous example shown in FIG.

[0124] However, in this example, the battery charger IC 125 that charges the battery 112 of the aerosol generating device 110 is located in the charging case 120, not in the aerosol generating device 110 itself. Thus, all electronic control circuitry related to the charging process is located in the charging case 120. This in turn means that less circuitry needs to be located in the aerosol generating device 110. This allows the number of components of the aerosol generating device 110 to be reduced, so that a less complex and potentially smaller structure of the aerosol generating device 110 can be envisaged.

[0125] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like, should be understood in all instances as modified by the term "about." Also, all ranges include the maximum and minimum points disclosed, and include any intermediate ranges therein, which may or may not be specifically recited herein. Thus, in this context, the number A is understood as A±10%. Within this context, the number A may be considered to include a numerical value that is within the general standard error for the measurement of the property that the number A modifies. The number A may, in some cases, as used in the appended claims, deviate by the percentages recited above, provided that the amount by which A deviates does not materially affect the basic and novel property(ies) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed, and include any intermediate ranges therein, which may or may not be specifically recited herein.

Claims

1. A method for charging a rechargeable lithium ion battery in an aerosol generating system, comprising: - initiating charging of said battery; - monitoring an electrical parameter indicative of the charging rate of said battery; - determining the charge rate of the battery by monitoring the change in the electrical parameter over a given period of time; - comparing the determined charge rate with a reference charge rate, the reference charge rate being defined by an expected change in the monitored electrical parameter; - inhibiting the battery from being charged if the charge rate deviates from the reference charge rate.

2. a plurality of parameters indicative of the charge rate of the battery are monitored; the parameters indicative of the charging rate are the state of charge of the battery, the output voltage of the battery, and the charging current applied to the battery; the charging process includes different charging modes; 2. The method of claim 1, wherein the parameter indicative of the charge rate of the battery being monitored is selected from the plurality of parameters depending on the charging mode being applied.

3. the charging process includes a pre-charge mode, a current regulation mode and a voltage regulation mode; In the pre-charge mode and the constant current regulation mode, the parameter indicates that the charging rate is the output voltage of the battery; 3. The method of claim 2, wherein in the voltage regulation mode, the parameter indicative of the charge rate is the current drawn by the battery.

4. 10. The method of claim 1, wherein charging the battery is inhibited only after the charge rate is found to deviate from the reference charge rate at least a predetermined number of times.

5. 10. The method of claim 1, wherein charging of the battery is inhibited if the charge rate deviates from the reference charge rate by at least a predetermined deviation.

6. The method of claim 1 , wherein monitoring the electrical parameter comprises determining the electrical parameter at a first time and determining the electrical parameter at a second time.

7. 7. The method of claim 6, wherein determining the charge rate of the battery comprises calculating a ratio of the change in the electrical parameter determined at the first time and the second time to a time difference between the first time and the second time.

8. The method of claim 1 , wherein the reference charging rate is determined from a charging scheme stored in a data storage unit of the aerosol generating system.

9. The method of any preceding claim, wherein determining the charge rate comprises monitoring a change in the electrical parameter between a first time and a second time.

10. 9. The method of claim 8, wherein determining that the charge rate deviates from the reference charge rate comprises determining that the monitored change in the electrical parameter is less than the change in the monitored electrical parameter defined by the reference charge rate.

11. 1. A charge controller for an aerosol generating system, the charge controller comprising: - start charging the rechargeable lithium-ion battery, - monitoring an electrical parameter indicative of the charging rate of said battery by monitoring the change in said electrical parameter over a given period of time; - determining the charging rate of the battery; - comparing the determined charge rate with a reference charge rate, the reference charge rate being defined by an expected change in the monitored electrical parameter; a charge controller for an aerosol generating system configured to prevent the battery from being charged if the charge rate deviates from the reference charge rate by at least a predetermined deviation.

12. 1. An aerosol generating device comprising: a rechargeable lithium ion battery; a first power interface for connecting the rechargeable battery to an external power source; and a host controller for controlling power supply from the rechargeable battery to an electric heater, The host controller comprises the charge controller of claim 11 for charging the rechargeable lithium ion battery; or 12. An aerosol generating device comprising a battery charger IC comprising the charge controller of claim 11 for charging the rechargeable lithium ion battery.

13. A charging case for an aerosol generating device, the charging case comprising: a rechargeable battery; a first power interface for connecting the rechargeable battery of the charging case to an external power source; and a second power interface for connecting the rechargeable battery of the charging case to a rechargeable battery of the aerosol generating device; The charging case further comprises the charging controller of claim 11 for charging the rechargeable battery of the aerosol generating device.

14. A charging case for an aerosol generating device, the charging case comprising: a rechargeable lithium ion battery; a first power interface for connecting the rechargeable battery of the charging case to an external power source; and a second power interface for connecting the rechargeable battery of the charging case to a rechargeable battery of the aerosol generating device; the charging case further comprising a host microcontroller comprising the charge controller of claim 11 for charging the rechargeable lithium ion battery of the charging case; or 12. A charging case, the charging case comprising a battery charger IC comprising the charge controller of claim 11 for charging the rechargeable lithium ion battery of the charging case.

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