Leverage 50 AMP Hot Tub power source for EV Charging

Question

Question: Can I repurpose 50amp wiring intended for a hot tub to be used to install a 14/50 Nema outlet in the garage to charge my Electric car?

Background: I am planning on having a new 50 amp breaker installed in my breaker box, 35ft of Romex conduit run to the garage, and a 14/50 outlet. I know this is going to be somewhat pricey (waiting on estimates from the electrician). When looking at the breaker box today for something else, I noticed a 50amp breaker labeled "Hot Tub Disconnect". It made me wonder if maybe there is an existing power source I can leverage. I moved into this home 2 years ago and it does not have a hot tub.

Lo and behold, on the outer wall of my garage I found these two boxes a foot from each other. One looks to be a hot tub disconnect and the other has some power wires with wire nuts. Pictures below.

Assuming these wires are the 50amp power for the hot tub, can I just instead have it routed through the wall to the garage and have the outlet installed there?

Answer 1

TL;DR Yes, But Don't Do It

Yes, you can reuse the 50A feed for EV charging. You need to make sure the wires are appropriate size (6 AWG or larger if NM cable (a.k.a., Romex), 8 AWG or larger if individual wires), though if it turns out they were undersized you can use them (with a breaker change) for whatever ampacity they can handle. See an ampacity chart for details.

But don't install a 14-50. That is the wrong way to do things. Now that Stellantis is on board, all the major car manufacturers in the US are moving to NACS over the next 2 years, and providing adapters until then. So get an NACS charger (the Tesla charger is great, but others are perfectly fine as well) and hardwire it. That gives you a few advantages:

• One less piece of equipment. In particular, there are many reports of basic 14-50 receptacles (which may be fine for an oven, for example) not working reliably long-term for EV charging. This saves that cost.
• If your jurisdiction is currently on a version of the NEC that requires GFCI on 240V receptacles (many are, many are not, some have made specific exceptions to this rule, varies by jurisdiction), hardwiring avoids (legitimately) the requirement, saving additional money and avoiding certain types of problems.
• Unless you are planning to use the same receptacle for welding or some other high-power device, you're just going to leave the EV charger/cable plugged in to the receptacle all the time anyway, so you don't lose anything by hardwiring.