Patent Description:
Electronic vapour provision systems, electronic nicotine delivery systems, etc, which are collectively referred to herein as e-cigarettes, generally contain a reservoir of liquid which is to be vaporised. When a user sucks or draws on the device, this activates a heater to vaporise a small amount of liquid, which is then inhaled by the user. Most e-cigarettes include a re-chargeable battery for supplying electrical power to the heater and other electrical/electronic components, such as a sensor to detect inhalation. Some e-cigarettes have a cartridge section. After the nicotine or other liquid in this cartridge has been exhausted, the empty cartridge can be removed or separated from the e-cigarette and replaced with a new cartridge containing further nicotine.

E-cigarettes are often supplied in packs for protection and easy portability. Such packs may accommodate multiple e-cigarettes and/or replacement cartridges, thereby offering a backup facility if one e-cigarette (or its cartridge) is exhausted. An e-cigarette pack may also have the ability to re-charge an e-cigarette, again helping to ensure good operating availability of the e-cigarette for a user. Such a pack may be provided with a cylindrical hole for receiving an e-cigarette for recharging, the hole generally reflecting the elongated, cylindrical shape of an e-cigarette. When the e-cigarette is located in the hole, the battery can be re-charged by a suitable wired or wireless connection (a wireless connection may rely upon induction charging). In some packs, the cylindrical hole may receive the entire e-cigarette for re-charging, while in other packs only a portion of the e-cigarette may be received into the hole.

In some devices, the pack must be connected to a power supply, e.g. a mains outlet or USB connection, during re-charging of the e-cigarette battery. In this case, the pack is typically acting as a convenient device for holding and interfacing to the e-cigarette during re-charging. In other devices, the pack itself is provided with a battery (or other charge storage facility). The pack battery allows the e-cigarette to be re-charged from the pack without the need for the pack to be connected to an external power supply during the re-charging, thereby providing greater convenience for a user.

The pack battery will be depleted in due course, and so is generally provided with its own re-charging facility - typically again reliant upon some form of mains or USB connection. However, since the pack is larger than an e-cigarette, it can accommodate a larger battery and therefore the pack does not have to be re-charged as frequently as an e-cigarette. For example, the charge capacity of a typical e-cigarette battery may be approximately <NUM> mAh, whereas the charge capacity of a typical pack battery might be in the region of <NUM> mAh. Accordingly, the pack battery is capable of re-charging the e-cigarette a few times at least before the pack battery itself needs to be re-charged.

Such a multiple or hierarchical arrangement of separately chargeable systems, namely firstly an e-cigarette and secondly a pack for the e-cigarette, is relatively rare. In contrast, most re-chargeable devices, e.g. mobile (cell) phones, are usually connected directly to a mains-powered charging supply (or else to an in-car charging supply). Furthermore, when the pack is connected to an external power supply, the pack may charge both the pack battery and an e-cigarette battery simultaneously, i.e. some electrical power from the external source is directed to the pack battery, while at the same time, some electrical power from the external source is directed to the e-cigarette for re-charging the battery within the e-cigarette. It is desirable for the operation and (re)charging of an e-cigarette and associated pack to be as safe, reliable and convenient for a user as possible.

<CIT> discloses a rechargeable e-cigarette comprising: a battery which provides a voltage output that has a maximum level when the battery is fully charged; a connector located on the exterior of the e-cigarette to allow the e-cigarette to be electrically connected to an external battery pack for re-charging without disassembly of the e-cigarette; and a recharging mechanism for re-charging the e-cigarette battery using power from the external battery pack when the connector is electrically connected to the external battery pack. <CIT> discloses a rechargeable pack for containing and recharging an e-cigarette.

A rechargeable pack is provided for containing and recharging an e-cigarette. The pack comprises a pack battery; a first connector which is electrically connectable to an external power source; a first recharging mechanism for re-charging the pack battery using the external power source when the first connector is electrically connected to the external power source; a tube for receiving an e-cigarette such that the e-cigarette can be contained within the recharging pack; a second connector which is electrically connectable to the e-cigarette when the e-cigarette is received within the tube; and a second recharging mechanism for re-charging the e-cigarette using the pack battery when the e-cigarette is electrically connected to the second connector. The second recharging mechanism is configured to provide protection against the pack battery providing excessive current through the second connector.

A rechargeable e-cigarette is provided comprising: a battery which provides a voltage output that has a maximum level when the battery is fully charged; a connector located on the exterior of the e-cigarette to allow the e-cigarette to be electrically connected to an external battery pack for re-charging without disassembly of the e-cigarette; and a recharging mechanism for re-charging the battery using power from the external battery pack when the connector is electrically connected to the external battery pack. The re-charging mechanism is configured to determine the voltage output of the battery, and to prevent re-charging of the battery if the voltage output of the battery is above a predefined threshold level, wherein said predefined threshold level is below the maximum voltage output level of the battery.

The present approach is not restricted to specific embodiments such as set out herein, but features from different embodiments may be combined, modified, omitted or replaced by the skilled person according to the circumstances of any given implementation.

Various embodiments of the invention will now be described in detail by way of example only with reference to the following drawings:.

<FIG> is a schematic diagram of an electronic vapour provision system such as an e-cigarette <NUM> in accordance with some embodiments of the invention (not to scale). The e-cigarette has a generally cylindrical shape, extending along a longitudinal axis indicated by dashed line LA, and comprises two main components, namely a body <NUM> and a cartomiser <NUM>. The cartomiser includes an internal chamber containing a reservoir of nicotine, a vaporiser (such as a heater), and a mouthpiece <NUM>. The reservoir may be a foam matrix or any other structure for retaining the nicotine until such time that it is required to be delivered to the vaporiser. The cartomiser <NUM> also includes a heater for vaporising the nicotine and may further include a wick or similar facility to transport a small amount of nicotine from the reservoir to a heating location on or adjacent the heater.

The body <NUM> includes a re-chargeable cell or battery to provide power to the e-cigarette <NUM> and a circuit board for generally controlling the e-cigarette. When the heater receives power from the battery, as controlled by the circuit board, the heater vaporises the nicotine and this vapour is then inhaled by a user through the mouthpiece.

The body <NUM> and cartomiser <NUM> are detachable from one another by separating in a direction parallel to the longitudinal axis LA, as shown in <FIG>, but are joined together when the device <NUM> is in use by a connection, indicated schematically in <FIG> as 25A and 25B, to provide mechanical and electrical connectivity between the body <NUM> and the cartomiser <NUM>. The electrical connector on the body <NUM> that is used to connect to the cartomiser also serves as a socket for connecting a charging device (not shown) when the body is detached from the cartomiser <NUM>. The other end of the charging device can be plugged into a USB socket to re-charge the cell in the body of the e-cigarette. In other implementations, a cable may be provided for direct connection between the electrical connector on the body and a USB socket.

The e-cigarette <NUM> is provided with one or more holes (not shown in <FIG>) for air inlet. These holes connect to an air passage through the e-cigarette <NUM> to the mouthpiece <NUM>. When a user inhales through the mouthpiece <NUM>, air is drawn into this air passage through the one or more air inlet holes, which are suitably located on the outside of the e-cigarette. This airflow (or the resulting change in pressure) is detected by a pressure sensor that in turn activates the heater to vaporise the nicotine from the cartridge. The airflow passes through, and combines with, the nicotine vapour, and this combination of airflow and nicotine vapour then passes out of the mouthpiece <NUM> to be inhaled by a user. The cartomiser <NUM> may be detached from the body <NUM> and disposed of when the supply of nicotine is exhausted (and replaced with another cartomiser if so desired).

It will be appreciated that the e-cigarette <NUM> shown in <FIG> is presented by way of example, and various other implementations can be adopted. For example, in some embodiments, the cartomiser <NUM> is provided as two separable components, namely a cartridge comprising the nicotine reservoir and mouthpiece (which can be replaced when the nicotine from the reservoir is exhausted), and a vaporiser comprising a heater (which is generally retained). In other embodiments, the e-cigarette <NUM>, the body <NUM> and the cartomiser <NUM> may be joined together permanently, so in effect they are just a single component. Some such unitary (one-piece) e-cigarettes may allow replenishing of a nicotine reservoir when exhausted using some suitable (re)supply mechanism; other one-piece e-cigarettes may be disposed of once the nicotine reservoir has been exhausted. Note that this latter type of device still generally supports re-charging because the battery will normally become depleted more quickly than the nicotine reservoir. The skilled person will be aware of many further possible designs and implementations of an e-cigarette.

<FIG> is a schematic (simplified) diagram of the body <NUM> of the e-cigarette of <FIG> in accordance with some embodiments of the invention. <FIG> can generally be regarded as a cross-section in a plane through the longitudinal axis LA of the e-cigarette. Note that various components and details of the body, e.g. such as wiring and more complex shaping, have been omitted from <FIG> for reasons of clarity.

As shown in <FIG>, the body <NUM> includes a battery or cell <NUM> for powering the e-cigarette <NUM>, as well as a chip, such as an application specific integrated circuit (ASIC) or microcontroller for controlling the e-cigarette <NUM>. The ASIC may be positioned alongside or at one end of the battery <NUM>. The ASIC is attached to a sensor unit <NUM> to detect an inhalation on mouthpiece <NUM> (or alternatively the sensor unit <NUM> may be provided on the ASIC itself). In response to such a detection, the ASIC provides power from the battery or cell <NUM> to a heater in the cartomiser to vaporise nicotine into the airflow which is inhaled by a user.

The body further includes a cap <NUM> to seal and protect the far (distal) end of the e-cigarette. There is an air inlet hole provided in or adjacent to the cap <NUM> to allow air to enter the body and flow past the sensor unit <NUM> when a user inhales on the mouthpiece <NUM>. This airflow therefore allows the sensor unit <NUM> to detect the user inhalation. The cap <NUM> may also comprise a pair of electrical contacts which allow the e-cigarette <NUM> to be charged using these electrical contacts (in addition to, or instead of, USB charging or the like using the connector 25B). This is explained in more detail below.

At the opposite end of the body <NUM> from the cap <NUM> is the connector 25B for joining the body <NUM> to the cartomiser <NUM>. The connector 25B provides mechanical and electrical connectivity between the body <NUM> and the cartomiser <NUM>. The connector 25B includes a body connector <NUM>, which is metallic (silver-plated in some embodiments) to serve as one terminal for electrical connection (positive or negative) to the cartomiser <NUM>. The connector 25B further includes an electrical contact <NUM> to provide a second terminal for electrical connection to the cartomiser <NUM> of opposite polarity to the first terminal, namely body connector <NUM>. The electrical contact <NUM> is mounted on a coil spring <NUM>. When the body <NUM> is attached to the cartomiser <NUM>, the connector 25A on the cartomiser pushes against the electrical contact <NUM> in such a manner as to compress the coil spring in an axial direction, i.e. in a direction parallel to (co-aligned with) the longitudinal axis LA. In view of the resilient nature of the spring <NUM>, this compression biases the spring <NUM> to expand, which has the effect of pushing the electrical contact <NUM> firmly against connector 25A, thereby helping to ensure good electrical connectivity between the body <NUM> and the cartomiser <NUM>. The body connector <NUM> and the electrical contact <NUM> are separated by a trestle <NUM>, which is made of a non-conductor (such as plastic) to provide good insulation between the two electrical terminals. The trestle <NUM> is shaped to assist with the mutual mechanical engagement of connectors 25A and 25B.

<FIG> is a schematic diagram of the cartomiser <NUM> of the e-cigarette of <FIG> in accordance with some embodiments of the invention. <FIG> can generally be regarded as a cross-section in a plane through the longitudinal axis LA of the e-cigarette. Note that various components and details of the body, e.g. such as wiring and more complex shaping, have been omitted from <FIG> for reasons of clarity.

The cartomiser <NUM> includes an air passage <NUM> extending along the central (longitudinal) axis of the cartomiser <NUM> from the mouthpiece <NUM> to the connector 25A for joining the cartomiser to the body <NUM>. A reservoir of nicotine <NUM> is provided around the air passage <NUM>. This reservoir <NUM> may be implemented, for example, by providing cotton or foam soaked in nicotine. The cartomiser also includes a heater <NUM> for heating nicotine from reservoir <NUM> to generate nicotine vapour to flow through air passage <NUM> and out through mouthpiece <NUM> in response to a user inhaling on the e-cigarette <NUM>. The heater is powered through lines <NUM> and <NUM>, which are in turn connected to opposing polarities (positive and negative, or vice versa) of the battery <NUM> via connector 25A (the details of the wiring between the power lines <NUM> and <NUM> and connector 25A are omitted from <FIG>).

The connector 25A includes an inner electrode <NUM>, which may be silver-plated or made of some other suitable metal. When the cartomiser <NUM> is connected to the body <NUM>, the inner electrode <NUM> contacts the electrical contact <NUM> of the body <NUM> to provide a first electrical path between the cartomiser and the body. In particular, as the connectors 25A and 25B are engaged, the inner electrode <NUM> pushes against the electrical contact <NUM> so as to compress the coil spring <NUM>, thereby helping to ensure good electrical contact between the inner electrode <NUM> and the electrical contact <NUM>.

The inner electrode <NUM> is surrounded by an insulating ring <NUM>, which may be made of plastic, rubber, silicone, or any other suitable material. The insulating ring is surrounded by the cartomiser connector <NUM>, which may be silver-plated or made of some other suitable metal or conducting material. When the cartomiser <NUM> is connected to the body <NUM>, the cartomiser connector <NUM> contacts the body connector <NUM> of the body <NUM> to provide a second electrical path between the cartomiser and the body. In other words, the inner electrode <NUM> and the cartomiser connector <NUM> serve as positive and negative terminals (or vice versa) for supplying power from the battery <NUM> in the body to the heater <NUM> in the cartomiser via supply lines <NUM> and <NUM> as appropriate.

The cartomiser connector <NUM> is provided with two lugs or tabs 380A, 380B, which extend in opposite directions away from the longitudinal axis of the e-cigarette. These tabs are used to provide a bayonet fitting in conjunction with the body connector <NUM> for connecting the cartomiser <NUM> to the body <NUM>. This bayonet fitting provides a secure and robust connection between the cartomiser <NUM> and the body <NUM>, so that the cartomiser and body are held in a fixed position relative to one another, without wobble or flexing, and the likelihood of any accidental disconnection is very small. At the same time, the bayonet fitting provides simple and rapid connection and disconnection by an insertion followed by a rotation for connection, and a rotation (in the reverse direction) followed by withdrawal for disconnection. It will be appreciated that other embodiments may use a different form of connection between the body <NUM> and the cartomiser <NUM>, such as a snap fit or a screw connection.

<FIG> is a schematic diagram of certain details of the connector 25B at the end of the body <NUM> in accordance with some embodiments of the invention (but omitting for clarity most of the internal structure of the connector as shown in <FIG>, such as trestle <NUM>). In particular, <FIG> shows the external housing <NUM> of the body <NUM>, which generally has the form of a cylindrical tube. This external housing <NUM> may comprise, for example, an inner tube of metal with an outer covering of paper or similar.

The body connector <NUM> extends from this external housing <NUM> of the body <NUM>. The body connector as shown in <FIG> comprises two main portions, a shaft portion <NUM> in the shape of a hollow cylindrical tube, which is sized to fit just inside the external housing <NUM> of the body <NUM>, and a lip portion <NUM> which is directed in a radially outward direction, away from the main longitudinal axis (LA) of the e-cigarette. Surrounding the shaft portion <NUM> of the body connector <NUM>, where the shaft portion does not overlap with the external housing <NUM>, is a collar or sleeve <NUM>, which is again in a shape of a cylindrical tube. The collar <NUM> is retained between the lip portion <NUM> of the body connector <NUM> and the external housing <NUM> of the body, which together prevent movement of the collar <NUM> in an axial direction (i.e. parallel to axis LA). However, collar <NUM> may be free to rotate around the shaft portion <NUM> (and hence also axis LA).

As mentioned above, the cap <NUM> is provided with an air inlet hole to allow air to flow past sensor <NUM> when a user inhales on the mouthpiece <NUM>. However, the majority of air that enters the device when a user inhales flows through collar <NUM> and body connector <NUM> as indicated by the two arrows in <FIG>. (The collar <NUM> and the body connector <NUM> are provided with holes, not shown in <FIG>, to support such airflow).

<FIG> shows the cap or tip <NUM> of the body <NUM> of the e-cigarette <NUM> in accordance with some embodiments of the invention. The cap <NUM> comprises a connector <NUM> comprising two electrical contacts 900A, 900B. The electrical contact 900B is a circular point-type contact located at the centre of the cap <NUM>. The electrical contact 900A is a circular ring which is concentric with the contact 900A and provided around the outside or rim of the cap <NUM>. It will, however, be appreciated that any other shape configuration of the electrical contacts could be used. The electrical contacts 900A, 900B are typically made of metal and are connectable to positive and negative electrical terminals of a recharging e-cigarette pack so as to (re)charge the e-cigarette (as explained in more detail later on). The tip of the e-cigarette, in particular connector <NUM>, may be covered by a user-removable protective tab or similar while shipping or before use to protect against the battery <NUM> accidentally discharging prior to first use by a consumer. This helps to ensure that the battery is delivered in an acceptable state to the consumer, and also that damage which might be caused by heating due to unexpected current flows from the battery is avoided.

<FIG> is a schematic diagram of the main functional components of the body <NUM> of the e-cigarette <NUM> of <FIG> in accordance with some embodiments of the invention. These components may be mounted on the circuit board provided within the body <NUM>, although depending on the particular configuration, in some embodiments, one or more of the components may instead be accommodated in the body to operate in conjunction with the circuit board, but is/are not physically mounted on the circuit board itself.

The body <NUM> includes the sensor unit <NUM> located in or adjacent to the air path through the body <NUM> from the air inlet to the air outlet (to the vaporiser). The sensor unit <NUM> includes a pressure drop sensor <NUM> and temperature sensor <NUM> (also in or adjacent to this air path). The body further includes a small speaker <NUM> and an electrical socket or connector 25B for connecting to the cartomiser <NUM> or to a USB charging device. (The body may also be provided with a tip connector <NUM>, such as discussed above in relation to <FIG>).

The microcontroller (e.g. an ASIC) <NUM> includes a CPU <NUM>. The operations of the CPU <NUM> and other electronic components, such as the pressure sensor <NUM>, are generally controlled at least in part by software programs running on the CPU (or other component). Such software programs may be stored in non-volatile memory, such as ROM, which can be integrated into the microcontroller <NUM> itself, or provided as a separate component. The CPU may access the ROM to load and execute individual software programs as and when required. The microcontroller <NUM> also contains appropriate communications interfaces (and control software) for communicating as appropriate with other devices in the body <NUM>, such as the pressure sensor <NUM>.

The CPU controls the speaker <NUM> to produce audio output to reflect conditions or states within the e-cigarette, such as a low battery warning. Different signals for signalling different states or conditions may be provided by utilising tones or beeps of different pitch and/or duration, and/or by providing multiple such beeps or tones. The e-cigarette may also be provided with an LED indicator (instead of or as well as speaker <NUM>) to provide visual output to a user, such as a warning of low battery charge.

As noted above, the e-cigarette <NUM> provides an air path from the air inlet through the e-cigarette, past the pressure drop sensor <NUM> and the heater (in the vaporiser or cartomiser <NUM>), to the mouthpiece <NUM>. Thus when a user inhales on the mouthpiece of the e-cigarette, the CPU <NUM> detects such inhalation based on information from the pressure drop sensor. In response to this detection, the CPU supplies power from the battery or cell <NUM> to the heater, which thereby heats and vaporises the nicotine from the wick for inhalation by the user. The level of power supplied to the heater may be controlled on the basis of information from the pressure sensor and/or the temperature sensor <NUM>, for example, to help regulate the nicotine delivery to the user according to the current ambient air pressure and temperature.

<FIG> illustrates a pack <NUM> for receiving and accommodating an e-cigarette in accordance with some embodiments of the invention. The pack comprises a body <NUM> which is provided with a hinged lid <NUM> that can open and close. The body <NUM> comprises an outer case or housing <NUM> which is fitted with an insert <NUM>. More particularly, the outer case <NUM> has an opening at the top, i.e. the end at which the lid is located, and the insert <NUM> is fitted into, and generally closes, this opening. The insert itself is provided with two openings or holes that extend down into the body <NUM> of the pack <NUM>. The first opening <NUM> comprises a substantially circular hole (in terms of cross-sectional shape). The first opening <NUM> is surrounded by an annular light element <NUM>. The second opening <NUM> in the insert comprises a pair of linked holes (only one of which is easily visible in <FIG>). The openings <NUM> and <NUM> (and more particularly, each of the pair of holes formed by opening <NUM>) can be used to receive an appropriately shaped object, such as an e-cigarette, a spare or used cartridge, etc. The dimensions of pack <NUM> are generally arranged so that an e-cigarette accommodated within openings <NUM> or <NUM> protrudes slightly out of this opening. This allows a user to readily discern the contents of pack <NUM> (as also helped by making lid <NUM> transparent), and also facilitates removal by a user of an e-cigarette located within one of these openings.

The pack <NUM> is further provided with a set of LED lights <NUM>. These are shown separated from the casing <NUM> in <FIG> in an exploded view, but in the assembled pack are integrated into the body <NUM> so as to lie flush with the outer casing <NUM>. These LED lights <NUM> can be used to indicate the charging state of the pack <NUM>, for example, whether it is fully charged, partly charged, or fully discharged. The LED lights <NUM> may also be used to indicate whether or not the pack <NUM> is currently charging (being charged). Such charging may be accomplished via a (mini or micro) USB link using a (mini or micro) USB connector located on the underside of the pack <NUM> (not visible in <FIG>).

<FIG> illustrates the main components that are housed within the body <NUM> of the pack <NUM>, more particularly, within housing <NUM>, in accordance with some embodiments of the invention (some minor components, such as internal wiring, are omitted for reasons of clarity). The body includes a battery unit <NUM> comprising a battery <NUM>, a printed circuit board (PCB) <NUM>, and a switch <NUM>. The body <NUM> can be seen to include a hinge or axle <NUM>, which provides a pivot about which the lid <NUM> is able to open and shut. The battery unit <NUM>, including the switch <NUM>, is located substantially below the hinge <NUM>. The switch <NUM> is activated as the lid <NUM> is opened or closed, and this activation of the switch then, in turn, is able to trigger activation of the LED lights, etc..

As illustrated in <FIG>, the insert <NUM> extends substantially to the bottom of the outer casing <NUM>. The insert defines a substantially cylindrical tube 132A extending down from opening <NUM> (see <FIG>), which is able to receive and hold an e-cigarette. The insert further includes two further substantially cylindrical tubes 131A, 131B, which overlap one another, extending down from opening <NUM> (see <FIG>) with a "figure-of-<NUM>" cross-section. Note that the bottom of tubes 131A and 131B may be closed by the insert itself <NUM>, or may be open, but abutting against the bottom of the outer casing <NUM>, which would then have the effect of again closing the bottom of the tubes 131A and 131B in order to retain an e-cigarette (or other item, such as a spare cartridge, therein). The configuration of the bottom of the tube 132A is explained in more detail later on.

Note that the battery <NUM> is relatively large - comparable in size, for example, with the opening <NUM> and associated tube 132A for receiving an e-cigarette. Consequently the battery <NUM> of the pack <NUM> will usually have significantly greater electrical storage capacity than a battery provided in an e-cigarette which may be accommodated within the pack. This allows the battery in the e-cigarette to be re-charged, typically several times, using the battery unit <NUM> of pack <NUM>, without the need for any additional, external power supply (such as a mains connection). This can be very convenient for a user, who may be in a location or situation which does not provide a ready connection to the mains power supply.

In order to support this re-charging of an e-cigarette stored within the pack <NUM>, the bottom portion of the tube 132A is located within an e-cigarette connection assembly <NUM>. The e-cigarette connection assembly <NUM> allows an electrical connection to be made between the pack <NUM> and the electrical contacts 900A, 900B on the cap <NUM> of the e-cigarette when the e-cigarette is inserted into the tube 132A, thus allowing the e-cigarette battery to be charged using the pack battery <NUM>. This is explained in more detail below.

The insert is provided with printed circuit boards (PCBs) <NUM> and <NUM>. The PCB <NUM> provides the main control functionality of the pack and is attached to tubes 131A, 131B by screws 136A, 136B, thereby retaining the PCB in the appropriate position relative to the tubes 131A, 131B. A mini-USB (or micro-USB) connector <NUM> is provided at the bottom of the PCB <NUM>, and is accessible through a corresponding aperture in the underside of the housing <NUM> of the pack body <NUM>. This USB connector can be used to connect an external power supply to the pack <NUM> for re-charging the battery <NUM> (and also any e-cigarette located in tube 132A). The USB connector may also be used, if so desired, for communications with the electronics of the pack and/or e-cigarette, for example to update software on the PCB <NUM> and/or to download usage data from the e-cigarette, etc. The PCB <NUM> is further provided with a set of physical and mechanical connectors <NUM> for retaining and operating the LED lighting <NUM>. In particular, the PCB <NUM> controls the LED lighting element <NUM> to provide an indication to a user about the current charging situation of the pack <NUM>, plus any other suitable information.

The PCB <NUM> is located on the outside of re-charging tube 132A, relatively near the top, i.e. closer to the hole or opening <NUM> for receiving an e-cigarette for re-charging. This PCB <NUM> incorporates at least one light emitting diode (LED), which is used to illuminate the annular light element <NUM>. The PCB <NUM>, LED and annular light element <NUM> are used to provide an indication to a user about the current charging situation of an e-cigarette located within tube 132A pack <NUM>, plus any other suitable information.

<FIG> show (in an exploded view) the e-cigarette connection assembly <NUM> in more detail in accordance with some embodiments of the invention. The e-cigarette connection assembly <NUM> comprises a base <NUM>, which is located on the base of the pack <NUM>, and a connector <NUM>, which has two electrical contacts 704A, 704B for making an electrical connection with the electrical contacts 900A, 900B on the cap <NUM> of the e-cigarette <NUM> when the e-cigarette <NUM> is inserted into the tube 132A. Specifically, the outer electrical contact 704A makes an electrical connection with electrical contact 900A on the e-cigarette <NUM> and the inner electrical contact 704B makes an electrical connection with the electrical contact 900B on the e-cigarette <NUM>. The electrical contacts 704A, 704B are connected to the PCB <NUM> via wires 708A, 708B and, under the control of the PCB <NUM>, act as positive and negative electrodes for charging the e-cigarette <NUM> with power supplied from the battery <NUM>. The electrical contacts 704A, 704B are spring-mounted on the base <NUM> so as to ensure good electrical connection with the electrical contacts 900A, 900B on the cap <NUM> of the e-cigarette. Electrical conductors connecting the electrical contacts 704A, 704B and the wires 708A, 708B may extend along the surface of the base <NUM> or may extend through a bore through the base <NUM>, for example.

The e-cigarette connection assembly <NUM> further comprises a cylindrical tube <NUM> which is fixed to the base <NUM>. A portion of the cylindrical tube <NUM> is configured to receive an end portion of the tube 132A. The inner diameter of the portion of the cylindrical tube <NUM> which receives the end portion of the tube 132A is set such that the outer surface of the end portion of the tube 132A frictionally engages with the inner surface of the cylindrical tube <NUM>. The inner surface of the cylindrical tube <NUM> further comprises a rib <NUM> which abuts the end of the tube 132A and ensures that only an end portion of the tube 132A having a predetermined length is able to enter the cylindrical tube <NUM>. The cylindrical tube <NUM> further comprises a groove <NUM> on its outer surface which engages with a rib <NUM> on the PCB <NUM>.

When the insert <NUM> and e-cigarette connection assembly <NUM> are inserted into the outer case <NUM>, the base <NUM> abuts the bottom inner surface of the outer case <NUM>. The insert <NUM> and e-cigarette connection assembly <NUM> are held in place within the outer case <NUM> (and also in relation to one another).

It will be appreciated that the configuration and arrangement of the pack and insert shown in <FIG>, <FIG> and <FIG> are provided by way of example, and the skilled person will be aware of many potential variations - e.g. the number, position, size and/or shape of holes <NUM>, <NUM> may vary from one embodiment to another, likewise the associated tubes 131A, 131B, 132A. Similarly, the details of the positioning, shape and size of the battery unit <NUM>, PCB <NUM>, and other components will generally vary from one embodiment to another, depending upon the particular circumstances and requirements of any given implementation. It is also noted that the shape and positioning of the electrical contacts 704A, 704B will be adapted according to different shape and positional configurations of electrical contacts 900A, 900B on the e-cigarette <NUM>.

The configuration and arrangement of the pack and insert as described above generally provide significant ease of use and convenience for a user. Thus the e-cigarette <NUM> can be quickly entered into pack <NUM> for storage when not in use. Furthermore, while stored in the pack <NUM>, the e-cigarette can be re-charged without requiring any disassembly of the e-cigarette. In other words, the re-charging can use connector <NUM> rather than connector 25B, hence there is no need to separate or disassemble the body <NUM> from the cartomiser <NUM>. Consequently the e-cigarette is then available for immediate use when so desired - e.g. without first having to disengage connector 25B from a complementary USB charging connector and then having to re-engage connector 25B on the body <NUM> with connector 25A on the cartomiser.

Nevertheless, it has been recognised there are some potential issues arising from this ease of use and convenience. Firstly, although it is very quick to insert an e-cigarette <NUM> into tube 132A for re-charging, there may also be a risk that some other (foreign) object is inserted into tube 132A, whether by accident or perhaps deliberately. Note that the connection between the e-cigarette connector <NUM> and the pack connector <NUM> at the bottom of tube 132A depends only on gravity, potentially enhanced by downward pressure onto the e-cigarette from pack lid <NUM> when closed (rather than involving some additional user manipulation, such as required by the bayonet fitting between the body <NUM> and the cartomiser <NUM> for joining connectors 25A and 25B together, or such as twisting for a screw fitting, or the required insertion force for a USB plug). Accordingly, a foreign object located within tube 132A may form an electrical connection with connector <NUM> at the bottom of the pack <NUM>. Depending upon the nature and material of the foreign object, this may, for example, cause a short circuit across connector <NUM>. This can lead to potential overheating of the foreign object, including a possible fire risk, and also overly rapid depletion of the pack battery <NUM>.

Secondly, because the pack <NUM> acts both as a container for storing and carrying the e-cigarette when not in use, and also as a re-charging system, the e-cigarette will therefore connect to the re-charging system on a frequent basis - in effect, after every use by a user. In contrast, with a dedicated USB re-charger, which does not provide convenient storage for the e-cigarette, the user will typically only re-charge the pack when the battery is depleted, or at least significantly depleted. However, conventional lithium ion batteries generally have a limited lifetime in terms of number of re-charging cycles, after which they start to degrade and have lower storage capacity. Although this number of re-charging cycles may be high, typically between <NUM> and <NUM>, such a limit might be reached in months if a battery is re-charged every day.

<FIG> and <FIG> schematically show some components of the e-cigarette <NUM> and pack <NUM>, respectively, in accordance with some embodiments of the invention. These components help to improve the safety and reliability of the various charging mechanisms provided for the e-cigarette <NUM> and pack <NUM>, including with regard to the two particular concerns identified above.

<FIG> schematically depicts some electrical components of the e-cigarette <NUM>. In addition to the connector <NUM>, battery <NUM> and connector 25B, which have already been discussed in relation to <FIG> and <FIG>, <FIG> also shows a tip charge PCB <NUM>, a temperature sensor <NUM>, and an over-current protection PCB <NUM>. It is noted that for the sake of clarity, not all electrical components of the e-cigarette <NUM> are included in <FIG> - e.g. some of the components already shown in <FIG> have been omitted.

The over-current protection PCB <NUM> monitors the current flowing through the connector 25B during operation of the e-cigarette <NUM>. It is recalled that, during use of the e-cigarette <NUM>, the CPU <NUM> detects when a user is drawing air through the e-cigarette using information from the sensor unit <NUM> and causes current to flow to the heater <NUM> in the cartomiser <NUM> via the connector 25B. If there is a short circuit at the heater, for example, there will be a sudden increase in current flowing through the heater <NUM> and connector 25B. The short circuit might occur for reasons such as an electrical fault at the heater, the heating circuit having been tampered with, excessive moisture making contact with the heater, etc.. A short circuit of the heater may risk damage occurring to the e-cigarette device or, worse, injury to the user.

Accordingly, the over-current protection PCB <NUM>, upon detection of a current through the connector 25B which is deemed too high (that is, above a certain predetermined threshold), causes the supply of current from the battery <NUM> to the connector 25B to be cut. This reduces the chance of damage to the e-cigarette <NUM> and of injury to the user due to such a short circuit.

The predetermined current threshold is set such that dangerously high currents indicative of a short circuit are cut off, but normal, non-dangerous variations in the current are not cut off (thus avoiding unnecessary inconvenience to the user). For example, the threshold for the current supply from the battery <NUM> to the heater <NUM> may be set somewhere in the range <NUM>-<NUM> milliAmps, or more precisely, in the range <NUM>-<NUM> milliAmps, such that any current greater than this threshold amount triggers a circuit cut off.

The PCB <NUM> may also cut off if the voltage of the battery <NUM> is too low, for example, below about <NUM> or <NUM>. This generally indicates that the battery is in a state of low charge, and this could potentially prevent correct (or satisfactory) operation of the heater coil.

The over-current protection PCB <NUM> may also monitor current flowing through the connector 25B, and/or voltage applied at connector 25B, during re-charging of the e-cigarette <NUM> via USB connector 25B. For example, the expected voltage applied by a USB charger to the USB connector 25B may be 5V, so that the over-voltage cut-off might be set, by way of illustration, at 6V. The over-current protection PCB <NUM> therefore provides protection for the e-cigarette <NUM> both during re-charging (against excessive re-charging voltage), and also during normal operation (against excessive current draw).

The tip charge PCB <NUM> acts as a controller for monitoring and controlling power flow from the pack <NUM> to the e-cigarette battery <NUM> during re-charging. For example, the tip charge PCB may cut off the power flow from the pack <NUM> to the battery <NUM> if the voltage and/or current received via connector <NUM> is too high - e.g. exceeds a predetermined threshold for voltage or current. The thresholds can be set to tolerate the full range of normal operating conditions, but to trigger (cut off) before a level that might start to cause damage to the e-cigarette <NUM>.

The tip charge PCB <NUM> is connected to the temperature sensor <NUM>. The temperature sensor <NUM> is in thermal contact with the battery <NUM> so as to be responsive to the temperature of the battery <NUM>. (Thus temperature sensor <NUM> is normally an additional device to temperature sensor <NUM> shown in <FIG>, since the former is positioned to measure the temperature of the battery <NUM>, while the latter is positioned to measure the temperature of the airflow into the e-cigarette).

As the battery <NUM> is (re)charged using the connector <NUM> (that is, when the e-cigarette is inserted into the tube 132A of the pack <NUM> so that the connector <NUM> makes electrical contact with the connector <NUM> of the pack), the battery will normally heat up. However, if the battery gets too hot (perhaps due to a fault in the battery or because the ambient temperature is very warm), this may cause damage to the e-cigarette <NUM>, to the pack <NUM> or, worse, injury to the user. Also, if the battery <NUM> is very cold (perhaps due to the ambient temperature being very cold), then attempting to charge the battery <NUM> may cause damage to it. Thus, the tip charge PCB <NUM> monitors the temperature of the battery <NUM> using information generated by the temperature sensor <NUM>. If the temperature gets too hot (that is, above a predetermined upper threshold) or too cold (that is, below a predetermined lower threshold), the tip charge PCB <NUM> cuts off the current supply to the battery <NUM> from the connector <NUM>. This reduces the chance of damage to the e-cigarette <NUM> or pack <NUM> or of injury to the user due to the battery <NUM> overheating, as well as reducing the chance of damage to the battery <NUM> by charging it when it is too cold.

The predetermined upper temperature threshold is set such that high temperatures indicative of potential battery overheating result in current to the battery <NUM> being cut off, whereas lower increases in battery temperature do not result in the current to the battery <NUM> being cut off. Similarly, the predetermined lower temperature threshold is set such that low temperatures which could damage the battery <NUM> result in current to the battery <NUM> being cut off, whereas smaller reductions in battery temperature do not result in current to the battery <NUM> being cut off. Examples of the upper and lower temperature thresholds are about <NUM> and about <NUM>, or about <NUM> and about <NUM>, respectively.

The tip charge PCB <NUM> also ensures that current is only supplied to the battery <NUM> for a predetermined time period before the current is cut off. This ensures that the battery <NUM> is not subjected to overcharging, in which the battery <NUM> continues to be charged even though it is already at full capacity (which might damage the battery <NUM>). The predetermined time period is set so that the battery can be charged to its full capacity (maximising the length of time that the user can use the e-cigarette without having to recharge it), but also avoiding overcharging of the battery <NUM>. For example, the predetermined time period may be set somewhere in the range <NUM> to <NUM> hours, such as between <NUM> and <NUM> hours.

Overall therefore, the over-current protection PCB <NUM> and/or the tip charging PCB <NUM> provide protection based on the parameters or dimensions set out below.

In the event that any of the above thresholds is breached, then the re-charge (or operation of the device as appropriate) can be terminated by activating a suitable cut-off. It will be appreciated that protection for each of the above four parameters or dimensions may generally be implemented as appropriate in the over-current protection PCB <NUM> and/or in the tip charge PCB <NUM>, where the former relates to the re-charge or normal operation through connector 25B, while the latter relates to re-charge through connector <NUM>.

Note that there is certain overlap or redundancy between the different dimensions of the protection. For example, the cut-off of the current supply to the battery <NUM> after a predetermined time period has elapsed will generally help to reduce the chance of the battery <NUM> becoming too hot during re-charging. However, this overlap gives greater protection, since if, for any reason, the temperature-monitoring function does not work correctly, then because current is only supplied to the battery <NUM> for the predetermined time period (rather than indefinitely), this may still prevent the battery from overheating.

The tip charge PCB <NUM> may also act to help preserve the operational lifetime of the battery <NUM>. Thus when the e-cigarette battery <NUM> is placed into the pack, tip charge PCB <NUM> may detect the current voltage of the battery <NUM>, and if this exceeds a predetermined charging threshold, the battery is not re-charged. In other words, in such circumstances, the tip charge PCB prevents the battery <NUM> from receiving external power from the pack <NUM> (akin to the situation if the PCB <NUM> receives an out-of-spec temperature reading from the temperature sensor <NUM>).

If we assume that the battery has a maximum voltage of <NUM>. 2V when fully charged, which is typical for a lithium ion battery, then the predetermined charging threshold may be in the range <NUM>-<NUM>. 1V, for example, <NUM>. At this level of charge, the battery <NUM> will generally appear to the user as fully charged. Furthermore, recharging back up to <NUM>. 2V will not deliver any significant increase in usage for the consumer, but may over time diminish the state of the battery. Thus the additional re-charging (if the threshold were not utilised) would tend to increase the rate of aging of the battery <NUM>, especially since repeated charging near the maximum voltage level of the battery tends to be most deleterious for the battery lifetime.

It will be appreciated that there are various ways for setting the predetermined charging threshold. For example, the predetermined charging threshold may be specified as an absolute voltage, or it may be specified relative to the maximum voltage of battery <NUM>. One possibility is that the predetermined threshold may be defined as a certain proportion of the maximum voltage, e.g. the predetermined threshold may be in the range <NUM>-<NUM>%, <NUM>-<NUM>%, or approximately <NUM>% of the (nominal) maximum voltage. Thus if the predetermined charging threshold is <NUM>% and the maximum voltage is <NUM>. 2V, then no (re)charging is performed if the voltage of battery <NUM> is above <NUM>. Another possibility is that the predetermined threshold may be defined as an offset from (below) the maximum voltage, e.g. the predetermined threshold may be an offset in the range <NUM>-<NUM>. 25V or <NUM>-<NUM>. Thus if the predetermined charging threshold is, for example, <NUM>. 15V below the (nominal) maximum voltage of <NUM>. 2V, then no (re)charging will be performed if the voltage of battery <NUM> is above <NUM>.

This functionality to protect the battery lifetime may be implemented in a different location from the tip charge PCB <NUM>, depending upon the requirements of any given implementation. For example, the functionality may be incorporated into the microcontroller <NUM> of the e-cigarette <NUM>. A further possibility is that the functionality is incorporated into the pack <NUM> (instead of, or possibly in addition to, implementing the functionality in the e-cigarette itself). This is discussed in more detail below.

More generally, the various functionality shown in <FIG> may be implemented using separate components. For example, the tip charge PCB <NUM> may be implemented as a separate component such as a BQ24040 PCB from Texas Instruments (this can help support the use of off-the-shelf components). Alternatively, one or both of the tip charge and over-current protection PCBs <NUM>, <NUM>, may be integrated as part of the microcontroller <NUM> (see <FIG>). A further possibility is that the tip charge and over-current protection PCBs <NUM>, <NUM> are integrated together into a single device which is separate from the microcontroller <NUM>.

As described above, the e-cigarette is provided with two contacts that can be used for re-charging, namely connector <NUM> (for charging via pack <NUM>), and also connector 25B, which can be used for charging via a (micro) USB connector when the e-cigarette is in a disassembled state (the body <NUM> and cartomiser <NUM> separated). Connector 25B can also be used for supplying power from the body to the cartomiser when the e-cigarette is in an assembled state. The tip charge PCB <NUM> provides protection and control in relation to charging the e-cigarette via connector <NUM>. The over-current protection PCB <NUM> provides protection and control in relation to supplying power from the body to the cartomiser.

The over-current protection PCB <NUM> may also provide protection and control in relation to charging the e-cigarette from an external power supply via connector 25B, analogous to the protection provided by tip charge PCB <NUM> when re-charging via connector <NUM>. For example, this protection and control may involve monitoring the current and/or voltage supplied from connector 25B, and cutting off the power supply to the battery if the current or voltage exceeds a respective limit. Further, the over-current protection PCB may cut off power if the duration (time) of charging exceeds some threshold level, or if the temperature of the e-cigarette is too hot or too cold. Note that over-current protection PCB <NUM> may have access to temperature sensor <NUM> for making this latter determination, or may be provided with its own, additional temperature sensor (not shown in <FIG>).

<FIG> schematically shows some electrical components of the recharge pack <NUM> in accordance with some embodiments of the invention. In addition to the connector <NUM>, battery <NUM> and connector <NUM>, as already discussed in relation to <FIG> and <FIG>, <FIG> also shows an over-current cut-off unit <NUM>, an over-voltage cut-off unit <NUM>, a multipoint control unit (MCU) <NUM>, a regulator PCB <NUM>, a temperature sensor <NUM> and a protection circuit module (PCM) <NUM>. Similar to <FIG>, certain components of the pack <NUM> have been omitted from <FIG> for the sake of clarity.

The pack <NUM> supports three main charging operations (modes). (<NUM>) When the connector <NUM> is electrically connected to a power source (such as a USB charging device), power flows from the power source via the connector <NUM> to the battery <NUM>. This allows the battery <NUM> to be charged. (<NUM>) When the connector <NUM> is electrically connected to a power source (such as a USB charging device), power also flows from the power source via the connectors <NUM> and <NUM> to an e-cigarette <NUM> (if present). This allows the battery <NUM> of the e-cigarette <NUM> to be charged (simultaneously with the pack battery <NUM>). (<NUM>) When the connector <NUM> of an e-cigarette <NUM> is electrically connected to the connector <NUM>, but there is no external power supply for the pack at connector <NUM>, power flows from the battery <NUM> to the e-cigarette <NUM> via the connector <NUM>. This allows the battery <NUM> of the e-cigarette <NUM> to be charged. These power flows are generally controllable by one or more of the over-current cut-off <NUM>, over-voltage cut-off <NUM>, regulating PCB <NUM>, PCM <NUM> and MCU <NUM>. The control of the battery charging and e-cigarette charging power flows will now be described in more detail.

The regulating PCB <NUM> is the principal controller of power for charging the battery <NUM> in that it regulates the current and voltage supplied to the battery <NUM> during charging. In some embodiments, the regulating PCB <NUM> is implemented using a MicrOne ME4057device; however, other implementations may use different devices (or may integrate the functionality of the regulating PCB <NUM> into other components).

The current and voltage are regulated by PCB <NUM> such that they remain substantially constant at predetermined values, which are selected to provide efficient, timely and safe charging of the battery <NUM> and to help enhance or at least maintain the battery's long-term lifespan (the long-time lifespan being related to the total number of times a rechargeable battery can be charged and recharged before it starts permanently losing its capacity).

When the battery <NUM> is a lithium ion (Li-ion) battery, the predetermined values of the current and voltage may be about <NUM>-500mA and about <NUM>. 2V respectively during charging. The predetermined values may also change over the course of a single battery charge. For example, when the battery <NUM> is first charged, the predetermined value of the current may be lower. Then, at a later time, when the battery has stored a certain amount of charge, the predetermined value of the current may be stepped up to about <NUM>-500mA, as above. This prevents the battery <NUM> from being subjected to a relatively large current when it is completely discharged (or close to being completely discharged), which might otherwise cause damage to the battery and reduce its long-term lifespan. Other implementations may have a different maximum current or voltage supply, such as somewhere in the region <NUM>-600mA and somewhere in the region <NUM>-6V (respectively).

The regulating PCB <NUM> is also connected to the temperature sensor <NUM>. The temperature sensor <NUM> is in thermal contact with the battery <NUM> so as to be responsive to the temperature of the battery <NUM>. As the battery <NUM> is charged using power supplied via the connector <NUM>, the battery will normally heat up. However, if the battery gets too hot (perhaps due to a fault in the battery or because the ambient temperature is very warm), this may cause damage to the battery <NUM> or pack <NUM> or, worse, injury to the user. Also, if the battery <NUM> is very cold (perhaps due to the ambient temperature being very cold), then attempting to charge the battery <NUM> may also cause damage to the battery <NUM>. Thus, the regulating PCB <NUM> monitors the temperature of the battery <NUM> using information provided by the temperature sensor <NUM>. If the temperature gets too hot (that is, above a certain predetermined upper threshold) or too cold (that is, below a predetermined lower threshold), then the regulating PCB <NUM> cuts off the current supply to the battery <NUM>. This reduces the chance of damage to the battery <NUM> or pack <NUM> and of injury to the user due the battery <NUM> overheating, and reduces the chance of damage to the battery <NUM> by charging it when it is too cold.

The predetermined upper temperature threshold is set such that high temperatures indicative of battery overheating result in current to the battery <NUM> being cut off, but normal (routine) increases in battery temperature, which do not risk damage, do not result in current to the battery <NUM> being cut off. Similarly, the predetermined lower temperature threshold is set such that for low temperatures, which might result in damage to the battery <NUM>, the current to the battery <NUM> is cut off. However, falls in battery temperature that remain within the specified normal operating limits do not result in current to the battery <NUM> being cut off. Examples of the upper and lower temperature thresholds are about <NUM> and about -<NUM>, respectively. However, for some batteries, the upper temperature threshold may be up to about <NUM> and the lower temperature threshold may be down to about -<NUM>. Typically the upper threshold is in the range <NUM> to <NUM>, while the lower threshold is in the range <NUM> to - <NUM>.

In some implementations, the pack <NUM> may be provided with a temperature sensor that measures ambient temperature within the pack (typically close to the location of any re-charging e-cigarette inside the pack). Again, this sensor may trigger a power cut-off if the temperature is found to rise above a certain threshold, such as <NUM>. Note that such a temperature sensor may be provided in addition to or instead of temperature sensor <NUM> as shown in <FIG> (which is intended to measure primarily the temperature of the battery <NUM>).

The regulating PCB <NUM> may also perform the voltage check on the e-cigarette <NUM> mentioned above. In particular, the regulating PCB <NUM> may detect the voltage level of battery <NUM> within the e-cigarette, typically based on the voltage appearing on contacts 900A, 900B as connected to connector <NUM>, and then decide to supply power to the e-cigarette <NUM> to re-charge the battery <NUM> providing the voltage level of battery <NUM> is not already above the predetermined charging threshold (which may be set in the various manners described above for e-cigarette <NUM>). This charging threshold protection may also be implemented by some other component in the pack <NUM> (other than regulating PCB <NUM>).

In addition to the current and voltage control implemented by the regulating PCB <NUM>, the pack <NUM> is provided with further safeguards against excessive voltages or currents that are too high and which may therefore cause damage to the battery <NUM> or other components of the pack (or injury to the user). For example, pack <NUM> also includes the over-current cut-off unit <NUM> and the over-voltage cut-off unit <NUM>.

The over-current cut-off unit <NUM> cuts off the power supplied from the connector <NUM> to the other components of the pack <NUM> (including the regulating PCB <NUM>) when it detects that the current exceeds a predetermined threshold. Even though the current supplied to the battery <NUM> is regulated by the regulating PCB <NUM> (as already described), the over-current cut-off unit <NUM> provides an extra layer of protection to the battery <NUM> and other pack components. For example, the over-current cut-off unit <NUM> helps to reduce the risk of damage to the components of the pack in the case that too much current is supplied via the connector <NUM> (this could happen, for example, if an unsuitable charging device which supplies too much current is connected to the connector <NUM>, or if one of the components of the pack short circuits).

The over-current cut-off unit <NUM> may be implemented, for example, using a thermal resettable fuse, which trips out by entering a high impedance state when the current exceeds the predetermined threshold. At a later time, when the temperature cools down, the thermal resettable fuse re-enters a low impedance state again, thereby allowing current to flow again (so that use of the pack <NUM> may be resumed). The predetermined current threshold is set such that a high current which might cause damage is cut off, but such that variations in the current within normal and acceptable operating parameters do not produce a cut-off. For example, the predetermined current threshold may be set at about <NUM> amp.

The over-voltage cut-off unit <NUM> cuts off the power supplied from the connector <NUM> to the other components of the pack <NUM> (including the regulating PCB <NUM>) if it detects that the supply voltage has exceeded a predetermined threshold. Even though the voltage supplied to the battery <NUM> is regulated by the regulating PCB <NUM> (as described above), the over-voltage cut-off unit <NUM> provides an extra layer of protection for the battery <NUM> and other pack components, thus reducing the risk of damage to the components in the pack (or potential injury to the user) in the case that too high a voltage is supplied via the connector <NUM>. Such a high voltage might occur, for example, if an unsuitable charging device that supplies too high a voltage were to be connected to the connector <NUM>. The predetermined voltage threshold is set such that a dangerously high voltage is cut off (i.e. one that might damage the device, or possibly cause injury to a user), but variations of the voltage within the normal (non-dangerous) operating range are not cut off. For example, the predetermined voltage threshold may be set at about 6V, thereby ensuring that a 5V USB charging device will not trigger the over-voltage cut-off unit <NUM>, but that higher voltages will trigger the over-voltage cut-off unit <NUM>.

The PCM <NUM>, which sits between the regulating PCB and the battery <NUM>, monitors the current and voltage between the battery <NUM> and other components of the pack (including the regulating PCB <NUM>) and trips the electrical connection between the battery <NUM> and the other pack components in the case that the current or voltage moves outside a predetermined current or voltage range (respectively). This monitoring is performed both for charging the battery <NUM> (from an external power supply via connector <NUM>), and also for discharging the battery <NUM> (to supply power to battery <NUM> in the e-cigarette <NUM> via connector <NUM>, as well as to other components in the pack, such as lighting <NUM>). In particular, during charging or discharging of the battery <NUM>, if either the current or voltage exceeds a predetermined upper threshold, then the electrical connection between the battery <NUM> and other pack components is tripped (cut off), i.e. the flow of power between the battery <NUM> and the other pack components is prevented or at least very significantly reduced. This helps to reduce the risk of too much current or voltage being supplied to or from the battery <NUM> and the problems associated with this (such as damage to the battery <NUM> and/or other components, injury to the user, etc.). The threshold for the over-voltage may be set, for example, at about <NUM>. 3V, while the threshold for over-current may be set, for example, in the range <NUM>-<NUM> amps, e.g. at about <NUM> amps.

Also, during discharging of the battery <NUM>, e.g. to re-charge battery <NUM> in the e-cigarette <NUM>, if the voltage from the battery <NUM> falls below a predetermined lower threshold, then the electrical connection between the battery <NUM> and the other pack components, such as connector <NUM>, is cut off. This helps to prevent damage to the battery <NUM> that might otherwise occur due the continued drawing of current from the battery when it has a low remaining capacity and is outputting a low voltage (this can happen with certain rechargeable batteries such as Li-ion batteries).

The PCM <NUM> may comprise a separate PCB or may (for example) be integrated as part of the battery <NUM>. Due to the position of the PCM <NUM> within the electrical circuit (that is, between the battery <NUM> and other pack components), the PCM <NUM> is able to detect voltage/current abnormalities which may not be detectable by the other voltage/current-controlling pack components (such as the regulator PCB <NUM>, over-current cut-off unit <NUM> and over-voltage cut-off unit <NUM>). The PCM <NUM> thus adds an extra layer of protection against the risk of damage to the battery <NUM> or any of the other pack components (or e-cigarette <NUM>), and against potential injury to the user caused by abnormal current or voltage values.

The PCM <NUM> may comprise any standard PCB suitable for detecting whether or not an applied voltage and/or current is within certain predetermined limits. Furthermore, the PCM <NUM> may comprise a metal-oxide-semiconductor field-effect transistor (MOSFET) for detecting when the current exceeds the predetermined current threshold.

The MCU <NUM> ensures that current is only supplied to the battery <NUM> during charging for a predetermined time period before it is cut off. This helps to ensure that the battery <NUM> is not subject to overcharging, in which the battery <NUM> is continuously charged even though it is at full capacity (this may damage the battery <NUM>). The predetermined time period is set to allow the battery to be charged to its full capacity (thereby maximising the length of time between charges for which the user can use the pack <NUM>, such as to recharge the e-cigarette <NUM>), but also avoiding overcharging of the battery <NUM>. For example, the predetermined time period may be set somewhere in the range <NUM> to <NUM> hours, such as between <NUM> and <NUM> hours.

The cut-off of the current supply to the battery <NUM> after the predetermined time period has elapsed may also help reduce the chance of the battery <NUM> becoming too hot or too cold. Although this is managed by the temperature-monitoring function of the regulating PCB <NUM> (as already described), if, for any reason, the temperature-monitoring function does not work correctly, then, because current is only supplied to the battery <NUM> for the predetermined time period (rather than indefinitely), the above-discussed problems associated with continuously supplying current to the battery <NUM> when it is too hot may at least be alleviated.

The MCU <NUM> also ensures that current is only supplied from the battery <NUM> during charging of an e-cigarette <NUM> via the connector <NUM> for a predetermined time before it is cut off. This provides an extra layer of protection to help prevent overcharging of the battery <NUM> of the e-cigarette <NUM> (in addition to the timed current cut-off function of the tip charge PCB <NUM> of the e-cigarette <NUM> itself, as described above). For example, the predetermined time period may be set somewhere in the range <NUM> to <NUM> hours, such as between <NUM> and <NUM> hours. Note that this cut-off applies irrespective of whether the current is being supplied to the e-cigarette <NUM> via the external power source and connector <NUM> or from the pack battery <NUM>.

The overcharging of the e-cigarette battery <NUM> may be avoided primarily by the predetermined e-cigarette charge time of the tip charge PCB <NUM>, with the predetermined e-cigarette charge time of the MCU <NUM> then being set at the same or a somewhat larger value so as to act as a back-up in the event that the timer of the MCU <NUM> experiences a fault and fails to cut off the current at the appropriate time. Thus, overcharging of the e-cigarette <NUM> can be avoided even if there is a failure in the timer function of the e-cigarette <NUM>.

A further protection mechanism implemented in the pack is to address the concern noted above that a foreign object can be introduced relatively easily into tube 132A. Furthermore, the foreign object may form an electrical connection with re-charge connector <NUM>, especially since this does not require any particular manipulation, such as screwing - (rather such connection can be formed just by gravity. Depending on the nature of the foreign object, this may potentially lead to (excessive) current being supplied through connector <NUM> to the foreign object, which might therefore overheat.

In order to provide protection against such a foreign object, the pack monitors the charging current provided to the e-cigarette <NUM> via connector <NUM>. This monitoring may be done, for example, by MCU <NUM> or PCM <NUM>, or by some other component (not shown in <FIG>) that sits directly on the circuit path to connector <NUM>.

The typical (nominal) charging current from the pack <NUM> to the e-cigarette is in the range <NUM>-<NUM> milliAmps (mA). A protection threshold is set sufficiently higher than this normal charging level, for example at 200mA, to allow for charging within the normal operating range plus a reasonable margin, but to minimise the risk of an excessive current supply to (and hence overheating in) the object being charged. It will be appreciated that this protection threshold may be set in various manners, such as by using an absolute voltage level (such as 200mA); or by using an offset from the nominal charging current (such as an excess current of 100mA or more above the nominal charging current); or by using a relative offset from the nominal charging current (such as an excess current of <NUM>% or more in relation to the nominal charging current).

If the measured (monitored) current exceeds the specified protection threshold, then the protection mechanism triggers to cut out the current to the connector <NUM>. Note that this cut-out not only provides a safety mechanism against a foreign object being inserted into tube 132A, but it also provides a safety mechanism against a faulty e-cigarette <NUM> being inserted for re-charging into tube 132A, e.g. an e-cigarette in which a short circuit has somehow developed (the temperature sensor <NUM> also provides some protection against such a faulty e-cigarette <NUM>).

This protection threshold may be implemented, for example, using a thermal resettable fuse, such as discussed above in relation to over-current cut-off <NUM>. When the protection threshold is exceeded, this may be indicated to the user as a fault condition on the pack by using lights <NUM> with an appropriate (predetermined) spatial and/or temporal pattern of illumination (other fault conditions discussed above may be indicated with other patterns of illumination).

The re-setting of this protection threshold and associated cut-off is activated in some embodiments by switch <NUM> (see <FIG>), which detects opening and closing of the pack lid <NUM>. For example, if the lid <NUM> of pack <NUM> is closed at the point of cut-off, then it is clear that the lid must be opened in order to remove any foreign body from the tube 132A. Therefore, re-setting of the protection threshold may be achieved by opening the lid. Note that in some embodiments, charging of the e-cigarette <NUM> in pack <NUM> may only commence once the lid has been closed, again as detected by switch <NUM>. Thus re-setting the protection mechanism by opening the lid does not activate charging per se, but rather enables charging when the lid is next closed. It will be appreciated that various other reset mechanisms are feasible, for example, an external user-activated reset switch, or an external user-activated on-off switch for the pack (switching off and then on again to reset).

The foreign object protection set out above can be regarded as a form of passive or indirect detection, in that the protection only triggers if an excess current is taken through connector <NUM>. Another form of passive or indirect detection may be to provide a sensor to monitor the temperature in or close to the tube 132A, thereby looking for an excess temperature as an indication that some foreign body (or possibly a defective e-cigarette) may be present in tube 132A. It is also possible to provide a direct or active protection mechanism, in which a positive check is performed by the pack to ensure that an item inserted into the tube 132A is an e-cigarette <NUM>. In contrast to the protection set out above, in which charging is initiated and continued unless a specific condition occurs (excess current), in this approach charging is not initiated (or perhaps initiated but then very quickly discontinued) unless a specific condition occurs - namely a positive outcome to this check.

There are various mechanisms by which such a check could be implemented. For example, the e-cigarette <NUM> includes a light ring located between the inner contact 900B and the outer contact 900A. The e-cigarette could be arranged to illuminate this light ring when external power is detected at the connector <NUM>, and the pack could then be provided with a photosensor to detect this illumination. If the photosensor provides confirmation of the illumination, this confirms that the inserted device is an e-cigarette <NUM>, and the power supply through connector <NUM> to connector <NUM> is continued. However, if no illumination is detected by the photosensor, this indicates that the inserted device is not an e-cigarette <NUM> (but presumably some foreign body), and the power supply through connector <NUM> to connector <NUM> is discontinued.

Overall therefore, the pack <NUM> of <FIG> may implement a large number of protection features such as: protection against high voltage and/or high current received from connector <NUM>, and/or from power being supplied from connector <NUM> for too long; protection against the pack <NUM> and/or battery <NUM> having too high (or too low) a temperature (this protection is relevant for all <NUM> of the charging modes defined above); protection against high voltage and/or high current being supplied to an e-cigarette <NUM> via connector <NUM>, and/or from power being supplied to the e-cigarette via connector <NUM> for too long (this current/voltage and timing protection can apply irrespective of whether the e-cigarette is being re-charged by an external power supply or by pack battery <NUM>). There may also be a cut-off implemented by PCB <NUM> if the voltage of pack battery <NUM> exceeds a predetermined level while the pack battery is re-charging (typically somewhere in the range <NUM>-<NUM>. 5V), or if the voltage of the pack battery <NUM> falls below a predetermined level while the pack battery is discharging (to the e-cigarette or other components of pack). This lower voltage may be set, for example, in the range <NUM>-3V, such as approximately <NUM>. There may also be protection against the presence of a foreign body in the re-charging tube 132A, as described above.

It will be appreciated that there are many different potential implementations for such active protection. For example, lighting may be provided elsewhere on the e-cigarette to indicate the presence of e-cigarette <NUM> in tube 132A (instead of or in addition to the tip lighting). A further possibility is that the external surface of the e-cigarette is provided with some particular marking (such as a bar code or logo) that can be recognised and validated by the pack. A further possibility is that the pack <NUM> and the e-cigarette <NUM> are provided with some suitable communications facility, e.g. a wireless Bluetooth link, or else some communications ability through connectors <NUM> and <NUM>, whereby the pack is able to confirm the identity of the e-cigarette <NUM>.

It will be appreciated that many variations in the implementation of e-cigarette <NUM> and pack <NUM> will be apparent to a person of ordinary skill in the art. For example, the components of <FIG>, such as the regulating PCB <NUM>, PCM <NUM> or MCU <NUM> may be provided as individual devices, or one or more of such components may be integrated together, for example, as part of the PCBs <NUM>, <NUM> and/or <NUM> shown in <FIG>. Alternatively, one or more of them may be separate components. In addition, the functionality may be distributed differently between the various components. Similarly, there are numerous potential variations for the connector <NUM> of the pack <NUM> and the connector <NUM> of the e-cigarette <NUM>. For example, the connectors <NUM>, <NUM> may vary in position, size, shape, etc., so long as the connectors <NUM> and <NUM> are able to provide an electrical connection with each other to allow current to flow from the battery <NUM> of the pack <NUM> to the battery <NUM> of the e-cigarette.

The various safety components of the e-cigarette <NUM> and the pack <NUM>, as described above, inter alia, with reference to <FIG> and <FIG>, all contribute to the overall control of the e-cigarette <NUM> and pack <NUM> during charging of both the e-cigarette <NUM> and the pack <NUM>, as well as during normal operation of the e-cigarette by the user. This results in a rechargeable e-cigarette and pack that have enhanced reliability and safety. It will be appreciated that other implementations may incorporate only some (rather than all) of the above-mentioned safety components of the e-cigarette <NUM> and/or pack <NUM>, and/or may potentially incorporate additional safety components.

Furthermore, the approach described herein can be extended to a range of electronic vapour provision systems, such as heat-not-burn devices (which may include some plant matter or extract, for example, tobacco leaf, which is then heated or provided with steam to produce the desired vapour). One example of such an alternative form of electronic vapour provision system is described in <CIT>, which discloses an inhaler containing an evaporator based on a composite planar structure that incorporates both a heating mechanism and wicking mechanism.

Claim 1:
A rechargeable e-cigarette (<NUM>) comprising:
a battery (<NUM>) which provides a voltage output that has a maximum level when the battery is fully charged;
a connector (<NUM>) located on the exterior of the e-cigarette to allow the e-cigarette to be electrically connected to an external battery pack for re-charging without disassembly of the e-cigarette; and
a recharging mechanism (<NUM>) for re-charging the battery using power from the external battery pack when the connector is electrically connected to the external battery pack;
characterised in that
the re-charging mechanism is configured to determine the voltage output of the battery, and to prevent re-charging of the battery if the voltage output of the battery is above a predefined threshold level, wherein said predefined threshold level is below the maximum voltage output level of the battery.