I use my 510 atomizers on 3.7V, for 7 to 10 days, when their are still fabulous, until their resistance increases all by itself due to many factors, so I move them to be used on the 6V mode of vaping where their perform perfectly and even better and with better consistency and for months...Sometimes, and after using them for weeks at 6V, they get cleaned up from liquid residues and drop back in resistance, so I use them back at 3.7V...And if by any chance their resistance increases even more (which is rare), they become even better at 7V.