DCT is a generic term indicative of a dual coil tank. In fact any tank other than on a mod of some sort is most likely only a single coil. A single coil cartomizer in the tank instead of a dual coil. Reason being with 2 coils you need high volts because you're splitting the volts between the coils. The 1000mah only refers to the available charge of the device. The output voltage is still going to be restricted to at most 4.8v. Which is more than enough for a single coil but not enough for a dual coil.