I've been using an 18650 battery source for the longest time. I always found that CE2 type carts started to suck really quickly I guess due to buildup. When I say quickly I mean sometimes even clean + after just 1/2 way through a tank. I happetned to leave my big battery source at work and had to use my old ego-t type bat. What the hell is going on here... I've done 4 cart refills and with the CE2 type carts and and the carts are still perfect??? I thought that voltage + resistance is just that and that both of the batteries are 3.7v, the cart resistance is fixed so what gives??? My guess is that the 18650 is delivering 3.7 under load whereas the ego is maybe not, hence I am essentially vaping at a lower voltage which happens to be working well with my juice, is that it? I am very wowed by this, after extensively testing some ce2 types with most of the old problems worked out, I just wasn't happy but I'm super happy with the smaller bat!?! thx