What is an 18650 battery?

Most people are familiar with the A, AA, and AAA battery sizes, but have never heard of an 18650. Manufacturers that produce lithium ion cells have a special battery called the 18650, named after its size as it is 18 mm wide and 65 mm tall. The nominal voltage is more than twice that of AA cells – at 3.6V each.


Lithium-ion is the battery chemistry with the most potential and fastest growth. Out of all metals, lithium provides the largest energy density for weight.

Commodity cell

The 18650 is the most economical of all li-ion cells. Standardization from the laptop and electric vehicle industries continues to drive the price down.

Low maintenance

Li-ion is a truly low maintenance battery that has no memory, requires no scheduled cycling, and has a very low self-discharge rate.


Lithium ion is part of a new generation of rechargeable batteries that has been in development and improving since the 1990s.

Research & Development

Researchers are constantly improving lithium ion cells. New chemical combinations are introduced bi-annually and progress is made quickly.

Very high current applications

Specialty applications like vaporizers and power-tools have created a line of batteries with very high amperage discharge ratings.