So I have been vaping for about six months now after eight years of smoking started with logics and moved to some cheap tank setup from a gas station to a protank 2. I recently bought the nautilus mini and am nothing but pleased( so much better than my pro tank2. Which I now have two sitting in my drawer which I won't use anymore after I bought the nautilus). My question for everyone is what would be a good battery upgrade for me to get from my vv spinner I am using now.