Pen style batteries like eGo-C are either automatic (very rare) or manually operated (typical).
Fact: Most users prefer manual as it gives more control and they are usually of a sealed type, so less prone to failure should a leak/spill occur.
Capacities can range from 320mAh for an E-smart type battery (similar in diameter to a regular cigarette) to over 1600mAh and closer in diameter to a White Board marker.
Types can range from standard regulated voltage output to variable voltage (and or wattage in some cases) and some also have passthrough ability, this allows to user to continue to vape whilst the battery is being recharged.
These batteries are for use in larger MOD type e-Cigarette devices.
eGo-T Upgrade MOD, VMax, Provari, eGo APV MOD V2, Lavatube, Epicstorm etc
They are listed by:
Manufacturer or Brand then by Size, then by Type, then by rated Capacity.
ie: AW - 18650 - IMR - 2000mAh