I've googled, checked various Vaper's terminology pages, and can't seem to find what 'evod' refers to exactly. I realize it's a battery, but is 'EVOD' an acronym? If so, what does E.V.O.D stand for? I see it ref'd to as 'eVOD', 'EVOD', or all lower case 'evod' on different websites, and in this...