Can I use my garage's three-prong dryer outlet?
 

Am I able to get an adaptor to switch from a three to four prong outlet in order to plug in the 240 plug for my etron?

Is this safe, will I get the full potential from the 240 outlet, and would I be able to use a splitter of sorts so that I could still keep my dryer plugged in?

Thanks in advance!

No personal experience but maybe this one will do: https://www.bsaelectronics.com/collections/dryer-buddys

They do make adapters that are not as expensive as the one previously mentioned:
However, as you can see from the pictures you will be missing the ground connection. The Audi EVSE seems sensitive about the ground from what I read which may keep this from working. I would probably switch out the outlet as dryers are supposed to use the 4-prong connector nowadays according to code. But of course this requires there to be a proper ground in the gang box for this to properly work.

Yes you may. That’s how I’ve been charging mine using NEMA 6-50 with an adapter. I’ve been charging at 8.4-8.8KW/H. I would definitely check the AMP fuse on your breaker box to make sure it has minimum of 50A. Hope that helps.

I’ve read about it somewhere that the EVSE doesn’t require a Neutral wire hence why you can use a dryer outlet to charge the vehicle using the correct adapter.

I did this until I had a ChargePoint EVSE I stalled in the garage on 50 amp circuit. My dryer was on 30 amp, so I had to use the half setting on the Audi evse otherwise the breaker did trip.

this is what I used
AC WORKS Electric Vehicle Charging Adapter for Tesla Use (10-30 3-Prong Dryer to Tesla)

Whoah, careful with that. A typical 3- (or 4-) prong dryer outlet is going to be a 30 amp, 220V circuit. The receptacle itself is only rated for 30 amps, even if the cabling behind it is rated for more.

A 30 amp dryer outlet is likely wired with 10 ga. cable back to the breaker box. Just swapping out a 30 amp breaker with a 50 amp one is likely to start a fire if the cabling connected to the breaker is not rated for that amount of current. It does not matter what size the breaker is -- the important thing is how big the wires are. 10 ga wire is only rated to 30 amps. To get to 50 amps continuous you have to go to 6 gauge wire, which is MUCH larger. I think you can technically get away with 8 gauge for a NEMA 14-50 receptacle for short runs and non-continuous use, but the wiring will get rather warm and you'll get a substantial amount of loss from heat before the power even makes it to the J1772 plug.

To OP: if you want to use an adapter from your 3-prong dryer outlet to the e-Tron charger's NEMA 14-50, you can do that, but I would *strongly* recommend that you leave the charger in its 50% mode, so it doesn't draw more than 25A.

^^^ This.^^^

I have been doing this on both of my E Trons. I keep it at 50% charge rate.

I tried that, but I had a NEMA 10-30 three-prong, and the Audi EVSE tripped out, even though I had an adapter. (The adapter branched the ground in the 14-50 off the neutral of the 10-30). I wound just buying a 16A EVSE off Amazon (about $180, if I recall) that was made for the 10-30 outlet, and leaving the Audi EVSE in the frunk. It works fine, and I've never needed more than a standard overnight charge to get the car back up to 80%.

Sure you can do it, but it's a kluge at best and you will eventually regret not putting in a dedicated 50 amp line with the proper wire size and 50 amp breaker. You have an $ 80,000 EV and cheaping out on the home charging circuit is not the way to go.

If you are in the USA, you get a $ 1,000 credit on your Federal Tax Return if you install a home charger this year 2020, in addition to the $ 7,500 tax credit on the E-Tron itself. Take advantage of that home charger installation credit, it expires end of December. I installed one myself, total cost of parts from Home Depot was less than $ 400.