I just got my Kanger KBox in from myvaporstore.com and when I first put a battery in it says I have a full charge. I then put the tank on and when I go to fire it up the led blinks 15 times signifying a low battery. I charged the battery some more and it still blinks. The firing pin on the box seems to be fine from the outside. When I press the button with no tank on it fires correctly but if I put the tank on it then it gives me the low battery flashes. And yes the tank is compatible with the kbox I have actually tried two separate tanks. Please give me an idea of the problem. Any help is appreciated.