My recommendation of a Volt was based on their 
superior cartos, good vapor, good flavor, easy to fill 

  Battery-wise one 3.7v is the same as the next except for the mah, can vary from ~180 to over 3000 mah. Depends on how big a rig you want to carry.  If you want to step up the voltage, 5v and 6v PVs are available or build-able, but with the low res available it doesn't make much sense for a newbie.
One of my favorite vapes is my roughstack with a 5v NiMH battery and a DoD auto-feeder modded to fit an ego type-B mega atty, not something most noobs would want to be seen on the street with....... 
