Let me start this off by saying there is nothing wrong with any of your hardware. I also have a nautilus mini, CF VV+ battery, and a subtank mini. The pin on the kanger doesn't stick out far enough to make good contact with the battery. I have an istick 30w in the mail so I'm not worried to much about it. But unless you find a way to get either pin on the tank or battery to protrude from its housing more, it won't fire. You can check this yourself by holding the two tanks 510 connections next to each other (opposite directions so the pins are both facing the base of the other tank) and you will notice the gap in between the kanger pin and nautilus base. In flashlights they use something called a rare earth magnet sometimes to fix such gaps when using button less batteries. I know nothing of it, but perhaps you could check it out. Or get another mod/battery. At the vape shop, my kanger fired perfectly fine on an istick 50w and an IPV 3.