Fast DC charging, e.g., 300 amps at 400 volts DC, is how you get those 120 kW charging rates--but only if your battery is on its last quarter tank when you start. Then the supercharger starts limiting the current and the rates start falling. When it falls to 10 kW (or 20 kW with dual chargers), why not switch to AC and use the car's built-in chargers? This would free up the 120 kW capacity of the fast DC inverters route to use for another charging stall. So instead of one charger splitting its feed between two stalls, it could do 3-4 instead. I bailed out of EE before we got to AC Machinery, so I trust someone will tell me why this won't work.