This is a bit rough but I just popped open an old car charger and rewired it with an old USB cable. I actually soldered a 901-510 adapter ( I didn't have an actual 510 connector on hand ) and placed a mini switch from radio shack in between. Add a few clumps of epoxy stick and voila!! Pretty simple and vapes like a champ. I am going to do another but will be a little more methodical and neater...lol.
E-cig: 5v passthrough - Cellular Car Charger Mod - YouTube
E-cig: 5v passthrough - Cellular Car Charger Mod - YouTube