The koopor mini is an awesome single 18650
mod. It offers up to 60 watts and tc if you ever decide to cross that bridge. I'm in love with mine... very portable. I personally won't own another
mod with a built in battery after my MVP 2.0. First was the frustration of it dying and having to charge it. Sure it had pass thru capability, but if you wasn't sitting still or what not it was pretty useless. The other thing is it's dead now. It'll last a few hours and that's it. The battery is pretty much shot and I'm out the $80 I paid for it. Granted I've had it several years and got my money out of it easily. It's just that if it had a removable battery I'd still have it working. I don't see what's so hard about taking out a battery and charging it. If it doesn't take an 18650 I won't purchase it for these reasons.