Do I need to upgrade my garage to NEMA 14-50?

Makes sense to me, even on 110v you can add some charge if you have enough time, and you have plenty of other charging options should the need arise.

It really depends on how reliable your charging station is at work. What happens if 3 or 4 of your co workers also decide to buy an EV ?

My garage has a 240 volt outlet in every parking stall, so I never have to worry about it. Most good electricians will give you a bid for free, might as well price it out and then decide. Make sure you read the home charging FAQ before you talk to an electrician. It will help you know if the contractor you work with is any good or not.

FAQ: Home Tesla charging infrastructure QA

If you have an extra circuit (say for some outlets you don't need), you could upgrade that wiring to 240V cheaply and double your charging speed.

If you have the capacity in your electrical panel, I would recommend installing the 50 amp 240V plug. It is really convenient to be able to charge in your own garage. What will you do on long weekends if you want to go on a road trip. Depending upon your situation the installation cost for a 50 amp plug may be very reasonable. A contractor friend and I completed ours in about 2 hours on a Saturday.

It's far more convenient to charge at home and, depending upon your workplace, it can be far less expensive. (If I used the one at my work it would be 61 cents per kWh vs. 9 cents at home.) Installing a 14-50 is generally not expensive--in the order of $300, depending on the length of wire required.

Edinct said:

Thanks very much for the advice so far. To answer a few questions, I have access to and capacity on the electrical panel, which we upgraded a few years ago after doing an addition. There's a run from the panel to the garage of about 8-10 feet, although would need to drill through a cinderblock wall to reach the garage. Still think the install would be about $300? And does pulling a permit add much costs?

Click to expand...

Permitting costs depend on the city. Typically they aren't that high. Note that some electricians inflate the price when they find out it's a car, so you may have to get multiple quotes, and some areas just have higher rates than others. You're only talking about $50 worth of materials.

I live on 110, but I have a lot less car.

When I do upgrade my garage, I plan to future-proof it. You might want to also. There may be a day when you have 3 EV's instead of 1, so why not spend a little more and get 3 outlets if your panel can handle it - and avoid calling the electrician back. (in my case there's going to be a trench to dig).

If you do end up using this car for road trips I think you'll like having 29 mph charging over 5 mph charging. One of the wonderful things about these cars is NOT having to stop for fuel - so avoiding that first Supercharger will be nice.

It'll be interesting to hear how long you live without upgrading. Hope you'll report back.

If your charging at work is free and available, you will do fine waiting.

Long term, you will appreciate faster charging at home. It's like watching paint dry charging from 120v. And I've only had a one day loner car.

jerry33 said:

some electricians inflate the price when they find out it's a car, so you may have to get multiple quotes

Click to expand...

Ha! Especially if the electrician finds out you're buying a very expensive Tesla. I would tell him that you can't wait to surprise your daughter with a used Nisssan Leaf or that you need the outlet for your new table saw. :biggrin:

Might the existing branch circuit be fed with Romex 12-2 that can support a 5-20 receptacle thus giving you approx. 125 miles of range overnight (12 hrs) with the proper $45 Tesla UMC 5-20 adapter?

Good Luck!

Edinct said:

Future-proofing it sounds like a great goal -- but how long before there are different infrastructure requirements? I'm thinking that waiting is future-proofing; it prevents you from implementing yesterday's solution. How confident is everyone that the upgrade will be the standard five or ten years from now?

Click to expand...

The NEMA 14-50 outlet will perhaps not always be the common outlet used, but a 50 amp circuit (per vehicle) should be more than enough to future proof the garage. Why not have them install a 100 amp sub-panel in the garage. It would be more expensive than wiring several outlets off the main panel, but would give you more flexibility in the future.

We installed a 100A sub-panel in ours, with two NEMA 14-50's wired to either side of the garage.

I did exactly what you are proposing for the first couple weeks. 120V charging at home, 208V 30A Chargepoint at work, good for 18mph. I had a HPWC installed at home, good for 80A charging if needed since I sometimes don't plan well. But honestly, I didn't use it more than a few times during the first year of ownership. Only when the Chagepoint got too competitive with Volt and Leaf owners did I give up and start charging at home. So your plan is totally doable.

The thing that is implied in the above replies is that you'll drive the car more than you think you will. It's addictive! And your TMC friends don't want to see your enjoyment of the car diminished by the inability to charge.

Do you have a gas or electric dryer? If it is gas, you may already have an unused 220 plug. If you have a gas dryer, take a look behind it to see if there is an unused 220 plug. It simply had this plug moved to my garage.

I have done ok the first month of Model S ownership with only 110V outlet in my garage at home. Although I will likely install a NEMA 14-50 outlet at some point, I've held off so far mainly because:
a) I didn't like the first 2 electrician estimates I got, 1 very expensive, the other cheap but of questionable reliability - so I want to get another quote or two, and
b) with the onset of Christmas holiday season and colder weather, I decided to hold off for a little bit. My particular install to a detached garage will either involve trenching & repairing concrete walkway or a long run of cable along some exterior walls, plus installation of a new subpanel and moving some circuits, so maybe I'll attack these early in the new year or in the spring.

Meanwhile I don't have a regular daily commute and my typical daily mileage is low. However now with an electric car I'm finding lots and lots of excuses to drive more than usual and I'm sure my average daily drive will increase. I know I will have road trips in the future and then my charging pattern will certainly change.

With 110V I get ~6km rated range/hr of charging at home, so usually no problem topping up to 90% overnight at home with my current usage. Here around town there are a lot of free L2 public chargers in places I frequent. So some days when I know I'll be near one of these public chargers I might not charge at home the night before just to make it worth my while to grab a charge for a couple hours when parked downtown. In 1 month of ownership so far this strategy has worked and I've only encountered public chargers busy once or twice. But as I say, I will likely eventually add 240V charging at home.

The electrician quotes are funny. mine ranged from $350 to $1700. I went with the $350 guy, city permit was $150 and that was across the board. parts really are about $50 and i would have been fine with installing myself if it wasn't for the piece of mind of having the permit pulled. the difference of having 3 miles per hour and 30 is surely worth a couple hundred bucks on a car that costs nearly 6 figures.

I rent a house and fully planned on doing it until I actually got the car. I work from home so I've discovered that even at 4 miles an hour, it's charging faster than I'm using it. Combine that with a supercharger 10 minutes away and a level II charger at my gym and I find that I'm generally never under 70% state of charge.

There is a cost benefit though. I'm not sure why but Tesla's calculator shows 240v as costing cheaper. Maybe the quicker charge is more efficient and thus cheaper. Either way, I think with my math I figured out that the 240 outlet would pay for itself in roughly a year.

Your plan sounds like it would work. But geez, it sounds like such a simple 240-volt installation that I wonder why you wouldn't give yourself the flexibility of faster charging at home.

(If you *don't* install a 240V receptacle, I second linkster's advice to try to charge on a 20A circuit rather than 15. Many household circuits are already 20A, even though the plugs may be of the 15A type. Check your panel, and if your garage circuit is on a 20A breaker and sized appropriately, change out the garage outlet to a 5-20 type and buy the Tesla adaptor.)

The logic of the OP and Mike K as a renter with so many fast charging options sticking with the 110V makes a lot of sense to me. If I was in a similar situation, I wouldn't have installed a HPWC and dual chargers.

I live in a hurricane & flood zone and my closest SC is 45 miles (50-60 minutes in average traffic) away. As one who plans for the worse and hopes for the best, I imagined (worse case) arriving home with 10 miles left and hearing an evacuation warning. I figure that in the time it would take to pack up my car, with 80A I'd have enough range to get out of harms way. Besides that, the Tesla recommended installer (who installs and services destination chargers in the Houston area) only charged $450 ($300 for NEMA 14-50).