sor

Hi all, I probably need to go through the user manual thoroughly, but I was wondering if anyone is aware of a way to limit the charging speed on the e-tron.

I’m taking a trip and I had a bright idea that I could possibly use the 30A dryer outlet at my destination. There are 14-30 to 14-50 adapters that Teslas often use, but you need to be able to limit the car to 24A charging rate. Otherwise it thinks it can pull 40A from the 14-50 with the standard frunk charger.

It may be more cost effective to just buy a travel charger that comes with a 14-30 plug and only advertises 24A to the car, however it seems like rate limit is a pretty common EV feature so it seems worth investigation.

JNealCox

Interesting question. You might find the info you are looking for in the thread: Can I use my garage's three-prong dryer outlet?
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For example: "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.
Whoah, careful with that (This is in reference to one writer who was interested in upping the circuit breaker from 30 to 50 A). 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."
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With the Audi charger you can switch between 100% and 50% by pressing and holding the Power button for a brief time. Hmm, maybe now I know why the Audi charger has that 50/100% option!

biff2bart

Wouldn't this be the way to do it? Total power pulled is just under 5kW IIRC. 5,000 / 240 = 21 amps...

sor

Thanks, I’ll take a look at the charger itself today. TBH I’d trust the charger limiting more anyway.

I also came across a travel charger last night that has five or six different plug attachments and will auto current limit based on the plug you’re using, pretty slick but it’s definitely more expensive option. Might be worth the investment though if I’m going to continue leasing j1772 EVs.

sor

I think I found a decent solution. Apparently they make 14-50 EV charging extension cords that have the neutral prong removed on the male side. This makes it possible to plug into 14-30, 14-50, and 14-60 outlets - you just need to be able to limit your charging draw and I think the 50% setting on the Audi charger will do.

The manual refers to a 14-30 adapter for the Audi charger but I have no idea how to get one, and I think the extension would be more useful anyway.