You can lower your nic level down from 24 to whatever you feel most comfortable with with a 5v but you dont have to. You just might not vape as much as you used too with the 3.7v device you were using. I've noticed when I switched to the Buzz from my ego that My nic level never changed I just don't chain vape anymore. I would try your current nic level at 5 and then decide from there whether it needs to be changed or not.