[rarestia]

A standard three prong (with ground) U.S. outlet is good for 15 Amp, should be connected to a 15A wring with a 15A breaker, and therefore plenty for a 12A load. If something else is on the line, the breaker should blow. Note the shoulds.

LMAO! 80/20 rule stipulates that when a breaker reaches 80% capacity, it will trip. You try to push 12A over a 15A circuit, and you can guarantee that POS electric car won't charge. If you have a dedicated 20A circuit, you might have a fighting chance, but most people will just assume, "Oh, the plug fits in this outlet, it must work."

A 12ga, 50 ft. 15A rated extension cord will get quite warm pushing 12A. They might get away with 8ga or 10ga 5-30, but that would require a dual-pole breaker on a dedicated circuit.

Gasoline is just so much easier.

[SoothingDave]

If your breakers are tripping at 80% of their rating, something is wrong with them.