Advice needed: Future-proofing my garage for home charging before finishing basement

[Blazing Whisper]

Hey everyone, my electric panel is located in the basement and I'm just about to get my basement finished. I plan to purchase a Model 3 in the next 12 months so I want to make sure I'm future-proofed for when I do.

When I finish the basement, it won't be easy to get my 240v wiring from my panel to the garage, so I want to do everything I can now to have it ready.

Does anyone have any advice on how to do this? Do I just get an electrician to install the 240v (50A?) cable from my panel to the garage and leave it hanging without it being connected to anything? Is a 50A sufficient for Model 3?

 

[alexhoff]

I would bring two 50A (4 AWG? Whatever the electrician recommends) to your garage but hookup one. The marginal cost is low, but thats how I would future proof.

 

[Goodtohave]

4g is perfect...everyone talks about “future proofing” but there is no reason EV’s will need more amperage to charge overnight. We would hope cars will be more efficient and not use huge batteries.

Worse case you will still need 4-6 hrs to charge from empty

 

[Roger Keay]

Tesla Model 3 can charge at up to 48 amps depending on the exact model. If you want the capability to charge at maximum speed then you have to install wire capable of 60 amps and a 60 amp breaker. The electrical code only allows 80% of rating for continuous load which results in 48 amps for the charger. You can choose to have a lower capacity circuit to charge your car which will charge more slowly but that might not be an important consideration for you. The charger has an internal switch that sets the maximum current that the car can draw from the circuit.

If you want full flexibility then you should have an electrician install a conduit (empty pipe) from the power panel to a junction box in the garage. The conduit must be sized for the maximum power you might want for the charger. When the time comes for the installation you can tell the electrician what power level you want. The electrician will determine the correct wire gauge and breaker size.

There may be cheaper ways than having a conduit installed which could depend on the construction of your house. If you were satisfied with 24 amps (30 amp breaker) then the installation required is like an electric dryer. You might be able to use the same cable type which would be less expensive than a conduit and pulling wires.

I suggest that you go over to the Tesla store in Oakville and have a chat with the staff. They probably know which electricians in the area specialize in EV charger installations. ​

 

[Imaginathan]

Yes it depends on which model you go with, we got the SR+ and just got the 50A put in on Friday. Ours only goes to 32 amps, so we requested the 50A for extra room while also asking for 6 gauge wire (TESLA recommendations, electrician said we could have done 8g). Just put a 14-50 receptacle in our carport with a weatherproof box. Any electrician can do this, might as well be safe and pay for quality work. Just tell them it’s for an RV to avoid that “TESLA tax” lol

 

[Blazing Whisper]

Thanks folks, that's very helpful. I think for full future-proofing I'll have the electrician put in a 60A wire while the basement is being done since I have an electrician coming in then. I'll have it go to a junction in the garage then install the wall connector when I get the car.

 

[Casmium]

For most people 20amps is sufficient, but 50amps is great if you eventually get two Ev's. The thicker the cable you run the better, you can always get a NEMA 14-50 outlet installed.

 

[Tessaract]

One way to do this effectively is to install a NMD 6-3 cable from your electrical panel to a disconnect box mounted on an inside wall of the garage. NMD is the least expensive cable type for actual 240V cable, and is suitable for protected locations (such as inside a wall/ceiling), and 6AWG is suitable for up to a 60A breaker (which would provide you with 240Vx48A continuous charging, the maximum possible for a Model 3). 60A disconnect boxes are readily and cheaply available from any big box home improvement store (Home Depot, Lowes). Once the disconnect box is installed on the inside wall of your garage, later, when you actually have a delivery date for your car, you can install a conduit with suitable wires or TECK-type cable from the disconnect box to your Wall Connector.

 

[ra88it]

I’d have a 100amp subpanel placed between the studs, and a few conduit run to blank boxes around the garage.

rear of car(s)
An outlet at each side of the front
And anywhere you think you might want an outlet later.

Then you can add later and it’s as simple as a new breaker in the subpanel and a short and easy pull for the electrician.

 

[JJFlash]

I’m waiting (impatiently!) for my M3 and went with 100 amp service to a sub-panel. That allowed me to go 60 amp to the wall charger. My wife will probably get a MY and we’ll see if it’s easy enough to share a charger. If not, it would be simple to run another wire from the sub-panel to the other side of the garage. I’d like to think that it’s pretty future proof. (The mess will be cleaned up in a garage reno). You can think about getting juice out to a sub-panel that you can use for future charging units. The wiring out from the main panel out to the garage wasn’t that big of a deal with a finished basement.

 

[ra88it]

I’m waiting (impatiently!) for my M3 and went with 100 amp service to a sub-panel. That allowed me to go 60 amp to the wall charger. My wife will probably get a MY and we’ll see if it’s easy enough to share a charger. If not, it would be simple to run another wire from the sub-panel to the other side of the garage. I’d like to think that it’s pretty future proof. (The mess will be cleaned up in a garage reno). You can think about getting juice out to a sub-panel that you can use for future charging units. The wiring out from the main panel out to the garage wasn’t that big of a deal with a finished basement.

if the boss ends up with a MY, then you’ll absolutely love another charger on the port side of the car, rather than sharing. At least this is my personal experience with the last 8yrs of EV ownership. 2x 50amp nema 14-50 or hardwired evse are perfect, especially with how affordable the highly optioned models are these days.

 

[RubinRA]

You might consider just putting in a standard 30 amp dryer plug (NEMA 14-30), which can charge at about 22mph. That's perfectly adequate for overnight charging, and if you sell the house to someone who doesn't have an electric car, they can just plug in a dryer. Or, better yet, try a 50 amp NEMA 14-50 outlet, which doesn't charge the car any faster, but which a future owner could use for a welder or RV if they didn't have an electric car. You can get Tesla adapters for either outlet to work with the portable charger that comes with the car.

 

[bwalter]

You might consider just putting in a standard 30 amp dryer plug (NEMA 14-30), which can charge at about 22mph. That's perfectly adequate for overnight charging, and if you sell the house to someone who doesn't have an electric car, they can just plug in a dryer. Or, better yet, try a 50 amp NEMA 14-50 outlet, which doesn't charge the car any faster, but which a future owner could use for a welder or RV if they didn't have an electric car. You can get Tesla adapters for either outlet to work with the portable charger that comes with the car.

Not sure why you say a 50 amp 14-50 won't charger faster than a 30 amp 14-30. The 14-30 would be good for 24 amps continuous while the 14-50 could do up to 40 amps continuous, though the Tesla mobile connector tops out at 32 amps. Still, 24 > 32.

I have a Model 3 LR AWD, so I had wiring good for 60 amps (48 amp continuous) installed since that's my max charge rate. However, I just have a 50 amp breaker and a NEMA 14-50 outlet and charge with the mobile connector.

I'd suggest the OP install a NEMA 14-50 outlet, possibly with wiring for a higher capacity though in my experience it's not really needed.

 

[ra88it]

I’d assume that not many have had to completely remodel a home and as such haven’t decided to future proof another project.

A subpanel gives so much flexibility and with conduit or smurf tube, you’ll never cut a hole after texture is applied. Sure, the current home EVSE is (commonly) 30-100a. What about in 2yrs when we all have 200kWh battery packs in our trucks?

 

[SilverString]

Perfect timing, go big.

 

[jamessssshi]

One 80A cable would be more than sufficient as HPWC can load share if you plan to get another Tesla and have another hpwc.

 

[mahagala]

it is also a good idea to run a Ethernet cable to the garage