The “Combined Charging System (CCS) Combo Coupler” can supply up to 500 amperes of current directly to the battery pack of a compatible electric vehicle, at a voltage between 200 and 1000 volts. Most fast chargers installed at present are limited to “only” 350 kilowatts of power. To avoid the charge cable being so thick and stiff that it is difficult to wrestle into connection with the car, the wires are thin enough so that resistive loss and heating is substantial, and the charge cable has active liquid cooling to prevent overheating!
More than a third of a megawatt sounds like a lot of power, but consider that the equivalent power delivered by a typical gasoline pump is around 5 megawatts. That’s why even fast charging an electric car takes substantially longer than “fill ’er up”.