The 18650 refers to a type of lithium battery.
Lithium-ion batteries: Because of their light weight, large capacity and no memory effect, lithium-ion batteries are widely used as power sources for many digital devices, although they are relatively expensive. Lithium ion battery energy density is very high, its capacity is the same weight of nickel metal hydride battery 1.5~2 times, and has a very low self-discharge rate.
The Type 18650 lithium-ion battery is the most commonly used lithium-ion battery in electronic products. It is often used as the battery cell in laptop computers. The definition of its model is as follows: for example, 18650, that is, the diameter of the battery is 18mm, the length is 65mm, 0 is the cylindrical type of battery.
