Charging Installation : Amp of circuit breakers and gauge of wire

Hardwire if possible

EV:

You can't use a 50A breaker on a 48 charge circuit. You must derate everything by 80%, or multiply load by 1.25 to get required circuit capacity.

48 amp EVSE needs at least 60 amp capacity circuit.
40 amp needs at least 50 capacity.
32 needs 40
24 needs 30
etc.

In truth wire gauge is supposed to be corrected for heat (let's say you're passing through an attic in a hot climate), but I seem to the only guy that knows it. No electrician I've ever contracted with knew or cared. For single circuit pulls you can save considerable money using aluminum, but know the bend radius can be a beach. Here is an ampacity link:

nec ampacities.pdf (usawire-cable.com)
or
Ampacity Charts | Wire Gauge Chart | Cerrowire

What ends up happening is we're in a no-mans-land when looking for a 48a continuous circuit. Some for instances that would work.
4/3 NM copper will do, but its pretty expensive.
6-6-6-6 SER would work too, and it should be cheaper.
4-4-4-6 Aluminum works too and is something like 1/4th the price, but it can be hard to find.

At this moment I'll do one of the latter two, mostly depending on what the electricians have, will do, etc. This as I'd rather not get into me buying cable in advance and most electricians are pretty narrow in what they keep in hand.

And yes, if 14-50 and you're going to be using them to capacity you really want a commercial grade plug.