Mr Rader2146 disagrees with me, but for me in my humble opinion, makes no sense to use dual coils. Dual coils are current dividers, it divides the current between two high resistances coils!. As Mr Rader24146 pointed out, that means that a dual coils splits the power output between the two coils, which means that the heat produced by each coil in the 'dual coil' is half of the heat produced by a 'single coil' coil. Hence a weaker vapor sensation produced by a dual coil system while dissipating the same amount of energy produced by a single coil system. So, the dual coil system is less energy efficient than a single coil system. That makes no sense right?
In order to get the same vapor and heat production in a dual coil system compared to a single coil system, a higher voltage is needed, let's say at least 5~6 volts is needed . This dual coil setting requires a higher current to heat the coils (which drains the battery faster) and to get a decent vapor and heat sensation production.
Remember that a current of 50mA (milliampere) is already quite dangerous, while these devices delivers currents in the order of 1000~3000 mA. A dual coil system uses even more current in order to get a decent vaping. So the less current you have to use, the better.
In the other hand, a single coil system is a 'what you see is what you get' system. Is a more simple but more effective system that transfers electrical energy to heat. The ohm law for this kind of system says that the more Voltage and resistance you have, the less current you have to spend in a single coil to get good amounts of power output, so it saves battery life and gives you a safer experience.
