Since the current topic is for regulated mods, I'm guessing you mean these?
With a regulated mod, coil resistance is irrelevant. What is relevant is the wattage setting that you will be using.
-If you use a good quality 15 amp CDR battery like the Samsung 30Q or Sony VTC6, then you are good up to 45 watts per battery; 90 watts using two; 135 watts for three batteries.
-If you use a good quality 20 amp CDR battery like the LG HG2 or Samsung 25R then you are good for 60 watts per battery. If using a 2-battery regulated mod, you're good for 120 watts as you have two batteries. If you are using a 3-battery mod, you're good for 180.
-If you use a single 25 amp CDR battery like the Sony VTC5A, then you are good for 75 watts per battery, 150 watts for two batteries, and 225 watts with three.
-If you use a single 30 amp CDR battery like the LG HB6 you are good up to 90 watts; with a pair of 30 amp CDR batteries you could safely do 180 watts.
WATTAGE PER SINGLE BATTERY on REGULATED MOD:
(Wattage doubles with 2 batteries)
Up to 45W:
Samsung 18650 30Q, 3000 mah 15 amp CDR
Sony 18650VTC6 3000mAh 15 amp CDR
Up to 60W:
LG 18650HG2 3000mah 20 amp CDR
LG 18650HE4 2500 mah 20 amp CDR
Samsung 18650-25R, 2500 mah 20 amp CDR
Sanyo UR18650NSX, 2500 mah 20 amp CDR
Sony 18650VTC5, 2600 mah 20 amp CDR
Sony 18650VTC4, 2100 mah 23 amp CDR
AW 18650 3000 mah 20 amp CDR
Up to 75W:
LG 18650 HD4 2100 mah 25 amp CDR
LG 18650 HD2 2000 mah 25 amp CDR
Samsung 18650-24S, 2500 mah 25 amp CDR
Sony 18650VTC5A, 2500 mah 25 amp CDR
Up to 90W:
LG18650HB6 1500mah 30 amp CDR
LG18650HB2 1500mAh 30 amp CDR
LG18650HB4 1500mAh 30 amp CDR
Samsung 18650-20S 2000mah 30 amp CDR
(new)