Your users manual will tell you the lowest coil resistance that you can use with your specific regulated mod.
Regulated mods and mechanical mods work a bit differently concerning resistance and batteries. A
mech mod is totally dependent upon the battery's amp rating and the coil resistance = Ohm's Law.
With a
regulated mod, coil resistance is irrelevant. The power supplied to the coil comes directly from the circuit board, not the battery. Regulated mods usually have "boost circuitry" to increase the battery power and "buck circuitry" to decrease battery power. However, the amp rating of the battery to the circuit board is still relevant. The battery must have the necessary amps to the circuit board to deliver the desired
wattage setting. Watts law applies here.
* Note that the amp rating of the battery determines the highest wattage the battery can deliver:
WATTAGE PER SINGLE BATTERY on REGULATED MOD:
(Total wattage doubles using 2 batteries; Triples using 3 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
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
Molicel 18650-P26A, 2600 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
It requires more power (amps) to drive a lower resistance coil than it does a higher resistance coil. So yes, the coil resistance (mechanical mod) or wattage setting (regulated mod) plays a part in how quickly your battery will be drained.
If you are using a single battery 60 watt regulated mod and you ask it to deliver 60 watts, then your battery will drain quite quickly. However, if you ask it to deliver only 30 watts, your battery will last much longer on a charge.
When using factory-made, drop-in coil heads for clearomizer tanks, the manufacturer gives "recommended wattage" ranges, usually written directly on the coil head.
Also, as you say you'll be using a dual coil RDA, keep in mind that using dual coils
halves the resistance. For example, two 1.0 ohm coils will have a total resistance of 0.5 ohm, not 2.0 ohm. Your regulated mod's ohm reader will read the total resistance of the two coils as 0.5 ohm.