For some reason an internet search isn't helping me. All I can find is how to use regulated devices. That's not a problem. Ok say I've got a .17ohm coil and I've got it set to 140w(I don't normally vape even half that high). Ohms law would say that's 28.7A. Now for pulsing that shouldn't be particularly hard on a pair of good cells. But is that how it works? The device only limits the voltage to 4.9V to make 28.7A to the coil? Or does it use pwm so the average is 140w buts it's not drawing the whole current from the cells. It could give full voltage and pulse the current then it might be only 20A. Otherwise I don't understand how the thing can go up to 220W. That's 40A