I recieved my mini 2 70w today along with a subtank mini, filled it with juice (4%nic), left the .5 coil in there, turned it down to 5 watts, reads 1.6 volts. Took a vape with air flow wide open, excellent vape. I guess the 30 watt would have been good enough for me, who knows , maybe get a 30 w...