What are these batteries used for?
For Mechanical Mods, VV Mods, and other electronic devices such as torch lights.
Available types of Batteries : 18350 (Small), 18490 (Medium) and 18650 (Large)
The 18 in the above 18350 etc, means the width of the battery, ie. size of 18mm. New bigger size batteries are also available such as 22650 batteries. They have a 22mm in size diameter.
First two digits represents the diameter,
the following two digits represents the height, which is measured in millimeters
0 = 18mm width, 65mm height
0 = 22mm width, 65mm height
0 = 14mm width, 50mm height
Best is to measure your current mod size so you can find out the type of battery you need for your mod.
Another feature that is with the battery that you will need to look out for is the Button Top. Some Mods such as the Provari, need a special battery that has a Button Top. Button Top batteries have a little nipple or button, that connects to the PCB that powers the device. Most other mods are not Button Tops.
Higher Amps are needed for the Mechanical Mods as they are capable of delivering high power without the battery getting hot. Highest Amp available are from Efest and SONY VTC series. The higher the amps will compensate of having a lower mAh power.
The higher the mAh means the usage of the device can be longer.