I didn't really know the right place to post this, but I just thought I'd if anyone else can verify this. My 510 T kit is a Joyetech and tank atomizers, and when I'm using batteries they just seem to be weaker and it takes a little bit longer to get a good drag off them then my Usb Passthrough. The atomizer sounds stronger on the passthrough then the battery too. I thought about getting different 510 batteries not from joyetech, but the ones by joyetech are notched alittle wider and deeper so I'm not sure if other batteries will give me a tighter draw. My wife has a kit from aquavapor.com called the 510 one, and their batteries are good but are alittle tight on the draw. I guess I maybe being a bit picky but maybe someone can give some good advice / information. 
