Since I've got my Reo's with RBAs my Provari has only been used to check resistance when I build coils. A Reo Grand uses an 18650 and holds 6ml of juice. Easily lasts the whole day. I use 1ohm micro coils in my ReoMizer2 attys. They are mechanical and built like a tank. Bottom feeding rocks, the vape of dripping and the storage capacity of a tank without the hassles or leaks.