silly... the batteries go in the kbox 75w minis upside down as well...
i have 3 of the topbox kits and 7 of the tanks, it's what i started with and only really has one issue..
if you drop it, the spring loaded gold coloured pin can get jammed up... a safety pin or small flathead screwdriver can be used to get it unstuck, just get the sharp end(with battery NOT in the mod) in where it's stuck and give it a wiggle. it's a common issue with spring loads and some of us being klutzes.
forgot to add... i've always used the LG HG2's in mine, yes both the battery and tank get warm since you are using them. the tanks will leak if you get the juice HOT(not warm) because the juice will become thinner with heat, so if that happens... hey you're chain vaping lol! batteries will warm with use and when charging.