An e-cigarette battery is the bottom half of an electronic cigarette. The rechargeable battery screws into the atomiser which, when topped with a cartridge, creates a complete electronic cigarette.

When an e-smoker takes a puff of their e-cigarette, a coloured LED on the end of the battery glows, imitating the 'cherry' on a tobacco cigarette. The LED works as a warning indicator too. It will flash a warning when a battery needs recharging and when too many puffs of an e-cigarette are taken in quick succession.

In addition to the original orange, LED colours now include funky blue, green and pink. These alternative colours help to avoid any confusion with tobacco cigarettes in no-smoking areas.

The charge in an e-cigarette battery varies greatly, depending largely upon the model of electronic cigarette and how often it's used.

For this reason, it's always a good idea to have one battery charging whilst another is in use. Most good suppliers will include 2 e-cigarette batteries in their starter kits.

Starter kits generally include a mains battery charger that charges a single e-cigarette battery at a time. If preferred, e-cigarette battery chargers which plug directly into a USB port can be purchased separately.

A third option and fairly recent innovation is the e-cigarette USB pass-through battery. This is also powered by your desktop or laptop computer via a USB port, but does away with the re-chargeable e-cigarette battery entirely.

Simply screw in your e-cigarette atomiser topped with a cartridge and puff-away in front of your computer for as long as you wish!