Electronic vapor provision device

1. An electronic vapor provision device comprising:

a body including a power cell and a processor, wherein the processor has a normal operation mode and a lower power sleep mode; and

a mouthpiece comprising a liquid store and a vaporizer, wherein the vaporizer is in fluid communication with the liquid store using a wick to transport liquid from the liquid store to the vaporizer for vaporization,

wherein the mouthpiece is connectable to the body in a co-axial manner, and

wherein the processor is configured to:

periodically check, during both the normal operation mode and the lower power sleep mode, whether the mouthpiece is connected to or disconnected from the body,

detect when the device has been inactive for a predetermined inactive time while the mouthpiece is connected to the body,

in response to such a detection of the device being inactive, and while the mouthpiece is connected to the body, transition from the normal operation mode into the lower power sleep mode,

detect, based on the periodic checking, and after the transition from the normal operation mode to the lower power sleep mode, that the mouthpiece has been disconnected from the body,

detect, based on the periodic checking, after the mouthpiece has been disconnected from the body, that the mouthpiece has been reconnected to the body, and

in response to such a detection of the disconnection and then reconnection, transition from the lower power sleep mode back into the normal operation mode.

2. The electronic vapor provision device of claim 1 , wherein the electronic vapor provision device is an electronic cigarette.

3. The electronic vapor provision device of claim 1 , wherein the lower power sleep mode is a lowest non-zero power mode of the device.

4. The electronic vapor provision device of claim 1 , wherein the electronic vapor provision device is inactive when not being used as a vapor provision device by a user.

5. The electronic vapor provision device of claim 1 , wherein the body comprises first and second body connection terminals, and the vaporizer comprises first and second vaporizer connection terminals,

the device configured such that when the vaporizer is connected to the body, the first body connection terminal is connected to the first vaporizer connection terminal and the second body connection terminal is connected to the second vaporizer connection terminal.

6. The electronic vapor provision device of claim 5 , wherein:

the body further includes a capacitor; and

the processor is further configured to first charge the capacitor and then detect whether the vaporizer is connected to the body by determining whether the capacitor is substantially discharged.

7. The electronic vapor provision device of claim 6 , wherein the capacitor is connected in parallel with the first and second body connection terminals.

8. The electronic vapor provision device of claim 6 , further comprising a computer configured to send out a pulse and charge the capacitor for a period of time substantially equal to the width of the pulse.

9. The electronic vapor provision device of claim 8 , wherein the pulse is a square wave.

10. A processor-implemented method of triggering a change, in the mode of a processor of an electronic vapor provision device, from a lower power sleep mode to a normal operation mode, wherein the electronic vapor provision device comprises a body comprising a power cell and the processor, and a mouthpiece comprising a liquid store and a vaporizer, wherein the vaporizer is in fluid communication with the liquid store using a wick to transport liquid from the liquid store to the vaporizer for vaporization, and the mouthpiece is connectable to the body in a co-axial manner, the method comprising:

periodically checking, during both the normal operation mode and the lower power sleep mode, whether the mouthpiece is connected to or disconnected from the body;

detecting when the device has been inactive for a predetermined inactive time while the mouthpiece is connected to the body;

in response to such a detection of the device being inactive, and while the mouthpiece is connected to the body, transitioning from the normal operation mode into the lower power sleep mode;

detecting, based on the periodic checking, and after the transition from the normal operation mode into the lower power sleep mode, that the mouthpiece has been disconnected from the body;

detecting, based on the periodic checking, after the mouthpiece has been disconnected from the body, that the mouthpiece has been reconnected to the body; and

in response to such a detection of the disconnection and then reconnection, transitioning from the lower power sleep mode back into the normal operation mode.