My only advice is if it seems too weak for you then consider 510 or KR808D-1 or their fat-battery versions, with manual
batteries
I don't know what model SS No 7 really is - with that male-thread style atomizer it could be RN4081, L88B/Trio, or others. Here is some info
http://www.e-cigarette-forum.com/fo...-7-compatible-batteries-switch-dif-model.html
And refill your carts. And when the stuffing gets old and cranky, try cutting blue foam almost as long and a tiny bit wider than the inside of your cart' s juice cup - taper the inner end a little bit. The cheap precut pieces at strictlyejuice.com for 510 may be big enough to cut down for your carts. Or you can buy the bulk for 10x the price as Marineland RiteSize U Foam Sleeve at Petsmart in the aquiirum dept.
There are lots of great eliquid sellers - check Backwoods Brew, FreedomSmokeUSA, Vaperite, VaporBomb, MadVapes, and there are so many others.
I started on a super-mini. It kept me happy for about 4 weeks, then I bought both the Joye 510 manual and the KR808D-1 manual (Vapor4Life.com model) which are the most supported models with parts sold by a bunch of vendors and excellent support for adapters, blank cartomizers, and upgrade paths. But I still vape my super-mini M401 (technically a mini with the longer batteries but carts the size of a supermini) - annoying carts but good flavor.