Relevant

While electronic cigarettes take many forms, they each generally employ the same basic components: a mouthpiece, a heating element, a rechargeable battery, and various electronic circuits.

Mouthpiece (cartridge)

The mouthpiece is a small disposable plastic cup affixed to the end of the tube. Inside, the piece contains an absorbent material that is moistened with a flavored nicotine liquid solution. The mouthpiece is referred to in the industry as a "cartridge" or "Cart". When the liquid in the cartridge has been depleted, it can either be refilled by the user, or replaced with another pre-filled cartridge.

Heating element (atomizer)

The heating element serves to vaporize the liquid in the mouthpiece so that it can be inhaled. This component is referred to in the industry as an "atomizer" or "atty". Some models combine atomizer and cartridge into one disposable component referred to as "cartomizer".

Battery and electronics

Most electronic cigarettes employ a lithium-ion rechargeable battery to power the heating element. Battery life varies depending on the battery type and size, frequency of use, and operating environment. Many different battery charger types are available, such as wall outlet, car, and USB. The battery is generally the largest component of an electronic cigarette.

Most electronic cigarettes employ an electronic airflow sensor to automatically activate upon inhalation, while some models instead have a manual button that the user must press while inhaling. Various other electronic circuits are usually employed as well, such as a timed cutoff switch to prevent overheating, and an LED to signal activation of the device. An orange-colored light is often chosen for its visual resemblance to actual burning tobacco in the front of the cigarette.

While some larger electronic cigarette models employ an independently replaceable standard-size battery cell, many models are too small to house a standard-size cell and instead require a proprietary component made by the electronic cigarette manufacturer. For those models, the battery and electronic components are housed within a single replaceable part, which is generally referred to in the industry simply as the "battery" — even though it actually contains many other components as well.