Can some one please inform me of how i can tell at what Voltage/Wattage I am actually vaping at on my istick 20w......im using a 1.6ohm coil that is reading at 1.7ohm and i have it set to 7.5w/3.5v......or at least thats what the screen on my istick is telling......i should have got the 30w Istick like i planned to........