That's exactly what I'm saying. Take your carto off and press the battery button; there is no circuit for current to flow. Drop a bunch of liquid on the end of your battery, hold the button and see if it "shorts out and smokes" - won't happen. Battery post connects to center post in carto, current flows into one end of a coiled high resistance metal alloy wire loop (commonly referred to as an atomizer), wire produces heat as a result of impedance to said current flow, atomizer coil is in near proximity to the liquid absorbed in the polyfill wick, liquid changes state to vapor as it heats up, as wick dries around the atomizer liquid from higher density regions of the wick migrate to fill the void of the vacated liquid, current flows out of wire coil to ground - end loop. The battery doesn't produce vapor, the atomizer does - and when the liquid near the atomizer is vaporized faster than it can be replenished due to inefficient wicking, or simply due to lack of liquid, it will definitely burn or at least produce a noticeable difference in vapor quality. I get lots of juice in my batteries (use only manuals for this reason), which is why I clean them very well every few days or a week at the outside. But, the juice that get's in my battery doesn't burn - only clogs up the flow of air. Vaporization of the juice only happens inside the carto near the atomizer, which was my main point. My secondary point was in agreement with Darri, in that a difference of 0.5V is not enough to cause the difference between normal vaporization and "burning".
The premium or wow carts have a lower resistance atomizer coil, which gets hotter (allows more current flow), and produces more vapor and throat hit - side effect is that the cart itself gets hot and the battery can get slightly warm. This is due entirely to conductive heating of the carto by the atomizer. Due to the higher current draw, the wow carts drain your batteries faster, and burn through juice faster as well. I think a lot more people have "burning" issues with wow or premium carts than with cool carts. I personally don't care much about throat hit, just vapor and nicotine, which is why I stick to cool carts.
I hope that made sense, sorry for the rambling response.