Electronic smoking device with reservoir detection element

An electronic smoking device (10) is provided that comprises a power supply/atomizer portion (12), a replaceable liquid reservoir portion (14), a liquid reservoir portion detection element (50) that is moveable between a first position and a second position, and an activation element (54) that is adapted to be operated by the liquid reservoir portion detection element when the latter is moved from the first position to the second position. The liquid reservoir portion comprises a cavity (46) and an engaging element (48) that partially blocks an opening of the cavity. The engaging element is adapted to engage with the liquid reservoir portion detection element during a process of coupling the portions (12, 14) so that the liquid reservoir portion detection element is moved toward the second position, thereby operating the activation element.