If I only have a 50A main in my garage, can I get a Wall Charger and run it at 40A to charge?

[MY-Y]

There is so much confusion on wire gauge needed for various charging currents on this forum that it might be worth a short sticky post for clarity.

For the full 48 amp charging, you need a 60 amp wire. Common choices include 4 gauge 60* C wire (e.g. NM) or 6 gauge 90* C wire (e.g. THHN in conduit). For 40 amp charging, you need a 50 amp wire. It's easy to find ampacity tables online.

As a reference point, I get 42 - 45 MPH charging at 48 amps, depending on the voltage at the time. The voltage reported by my MY is typically between 235 and 238 at 48 amps.

 

[spokey]

I had a 50A dedicated from the main panel in to the garage with 6 gauge THHN. I use the gen 2 mobile which I leave plugged in. I almost always charge at 30mph / 32A so I can go from pretty empty to pretty full over night. If these unprecedented times ever end maybe I'll be on trips again. In that case I'll unplug and take the mobile with me. Or if it becomes a habit, buy another mobile and keep that in the car. Still cheaper than the WC.

As for tidy, I bought the Tesla cable organizer - Cable Organizer (yeah expensive for a couple pieces of plastic). I think it keeps it neat. The electrician installing the circuit mounted the holster right under the outlet for me and the hook off to the side like the picture. It's next to the garage door so I just get out of the car, walk around the back and grab / plug in on the way in to the house.

The mobile is smart enough to change itself. Before the new circuit I was charging at 115jV. It knew enough to keep it at 12A. Now at 30 (32?). I think 30 or 32 is a max for the mobile.

 

[kadify]

I'm going to get the WC installed on my current 50A panel. It ends up being cheaper doing it this way than getting a 14-50/30 installed and then buying a second mobile connector (one for the car and one for garage). Prices came out to $721 to install the WC and $435 for installing a 14-50/30 plus by the time I buy a second mobile connector I'm at about $310 to get the mobile connector and one of the adapters to fit the plug.


I'm half considering upgrading the breaker and wiring to a higher amperage since the total cost for running a new wire is only an additional $500 BUT I think for the moment, it makes more sense to go with charging at 32A since it should be enough for most of my needs.