Do the watts and volts work together simultaneously? Like when I set it to what wattage I like, will it automatically adjust the volts and vis versa? I'm not too familiar with watts, so I'm just trying to learn. I just picked up my MVP today, and before that I was using an ego twist. As I understand it, with the MVP you can adjust the watts to what you like, and it will stay at that number until the battery runs out (unlike the twist where you have to keep turning up the volts as you use-- like if I had it at 4 volts but the battery was running low, it wouldn't truly be 4 volts). Is this correct?