Yes, you need an "empower" plug. I'll bet if you grasp the cable end in one hand, and the cigarette lighter end in the other, and pull gently, the cigarette lighter end will slide off, revealing a round tube almost an inch long, with two metallic prongs inside it. That's the "empower" plug

Note: If you look carefully where the cable goes into the cigarette lighter plug, you may see a small plastic tab you have to press down, in order to get the cigarette lighter end to release from the cable.