Just curious if there was a reason you installed a 20 amp outlet versus a 50 amp outlet? I installed a 30amp in my garage when I purchased my Volt, a decision I have come to regret. I am not sure if I will make the change or just charge my R1S at
I was just putting in a couple of circuits for my tools in the garage. Table saw, compressor etc... At least 10 years ago and had no thought of charging an EV. I don't drive very much, and hope that this circuit will work for charging. I'm guestimating charging it 5 times a month on my driving habits.
If I was paying an electrician to install an outlet, then yes I would get the biggest circuit within reason. Upping the amperage is incremental at that point.
You might be able to upgrade your circuit for not too much trouble. Depends on what wire and/or conduit they used. If they used jacketed wire like 10/3(typical house cable) then maybe they could replace it with THHN and get another 10 amps or more.
But hey I'm not an electrician so so please consult a professional.