There's already a standard EV charging port, called J1772, and the Tesla Model S comes with a J1772 adapter. A Tesla Supercharger has a maximum output of 100 k

There's already a standard EV charging port, called J1772, and the Tesla Model S comes with a J1772 adapter. A Tesla Supercharger has a maximum output of 100 kW (400V, 250A). J1772 level 2 has a maximum output of 19.2 kW (240V, 80A) but I believe most don't put out the maximum amps. If you have an EV with a small battery and you're trying to get around town, a J1772 stop might be useful. For a Tesla on a long distance trip, a J1772 stop won't be worthwhile on its own unless you're desperate. (If you're stopping anyway for some other reason, you might as well plug in if it's convenient.)