If you have a good commute, vaping as you go, and want to save your batteries for the rest of the day, I'll suggest a cheap ($10) truck stop 2.1 Amp USB cig lighter plug in and this:

Variable voltage passthrough (google that), no battery, consistent power, 510 and EGO threads. I've used it every day for a month or so, very happy with it. Got mine from Vapor Kings at a good price, don't even mount my batteries until I get to work, even use it with my iPad AC adapter sometimes.

Variable voltage passthrough (google that), no battery, consistent power, 510 and EGO threads. I've used it every day for a month or so, very happy with it. Got mine from Vapor Kings at a good price, don't even mount my batteries until I get to work, even use it with my iPad AC adapter sometimes.