I have a few shorty extensions I use on those batteries.
I use the Ego with a Joye Ego 650maH battery.
I use the Jessy M with the Jessy 650maH battery.
(I split two kits with Patty and we each have one of each.)
I use the Jessy most.. but I use the Ego through the day (they are two different flavors!)
I keep a few of those SmokTech 900maH batteries as my "Nobrand" ecig.. that I make a variety of ecigs from for various uses.
Generally I use a regular 510 atomizer (I like Bauway) and I put on a regular non see through black refill cartridge. This is for my vaping an odd flavor here or there "in between" vapes.
I do use them to mess around also....
I present Frankenvape.
Then, Patty wanted a monster of her own, so I made her a similar unit whose cartomizer (also dual coil)holds 2.5 ml
Please meet "The Bride of Frankenvape".
Although these monsters do not have the features, and smooth flavors that we get with our favorite ecigs, the Jessy, they do produce monster hits, and I have already provided a number of local friends with this Mod!
EDIT#1- I never use cartomizers for myself. I do not like them. The above "monsters" were made for a couple of friends with specific "wants".
Edit#2
Self cleaning atty... Yes
This seems to work great. It is actually the battery that holds the chips and memory. After 300 button pushes, the unit 's battery has a circuit that completes a connection and sets an ultrasonic vibration through the atty.
The lights go through a series of blinking when this occurs.. and I do notice a distinclty fresher and thicker vapor afterwards.