A capsule (6) contains a liquid (28) to be supplied to an atomizer (20) and is mounted on or in an electronic smoking device (1). The capsule (6) has a controller (40) including a memory, which receives data from and transmits data to control electronics (14) of the electronic smoking device (1). A capacitor in the capsule (6) is charged by the electronic smoking device (1) and powers the controller (40) during intermediate intervals. Electrical contacts (26, 48) of the capsule are connected to electrical contacts (24, 46) of the electronic smoking device (1) to charge the capacitor and exchange data.