Depends on your batteries, I guess. LR on the VV box mod they have will trip the circuit protection on the ultrafires they carry at around 4.7 or so volts. AW IMR 14500s (that you'll have to get elsewhere because madvapes doesn't carry them - kalamazoo vaper shop, clouds of vapor, super-t etc etc etc carry AW) can be used all the way to the top of the regulator trim (mine tops out around 6.8v) with a 1.5 ohm DC.
The regular 2XAA box mod isn't regulated voltage or variable voltage. I have never seen a single 3.7v battery trip the circuit with a dual coil attached. So, if you're just talking about the 2XAA box and not the VV box, then you will have no trouble running a 1.5 ohm DC.