Automatic batteries offer an experience most similar to smoking an actual cigarette, so they are typically preferred by new users. Automatic batteries are activated by air-flow, so there is nothing for the user to do other than inhale. With Manual batteries on the other hand, there is a small button which must be pressed for the unit to start working. Once the button is released, the unit will shut off. Manual batteries are typically preferred by experienced users that prefer more control over their electronic cigarette experience.