Efest is Decent. I use the 18350's in short mode.(Mini-eVic)
Panasonic CGR18650CH are Excellent. Amazon usually runs a special on 4 around $25.
As for youe Coil readings - eVic is Fast Read. i.e. eVic detects your tank the instant the center pin makes contact. If you are screwing it on slowly it will usually read a little high.(still loose when read)
You will also see a difference between a warm coil and one that has sat idle for a while.(normal)
For a dead accurate reading, turn eVic off. install tank. Power on.
I always put mine to sleep, then wake the eVic up for a reading
