Although I've heard conflicting comments, I've read that the dual coil cartomizers were originally intended to be used with eGo batteries so that those batteries could "hit" similar to their bigger brother mods with bigger batteries. I've also read that for a dual coil to truly shine, it needs at least 4.5v of power to get both coils going. The truth? I honestly don't know.
From my own experience, I did notice when I used them before, that they drained my batteries faster than the single coils that I now use. My flavor production, vapor quality, and throat hit have not suffered since switching to the single coils; in fact I tend to prefer the cooler, smoother vape that I get from them when used in my cartotanks on my APV's.