How many Amps to charge an EV?

[EddieWalker]

I have no plans of buying an EV, but I also never wanted a computer or a cell phone, so it would be silly of me to try to predict what I will or wont buy in the future.

I'm adding on a garage to my house. I'm running the wires for my outlets and lights, and I'm going to run power for my welder. For the welder, I want 50 amps. I can add an outlet along the way for an EV to plug into, but is 50 amps enough?

I was talking to a guy who said his daughter has an EV, and she had a 70 amp outlet installed. I never heard of this before. Should I buy bigger wire so I can run 70amps?

Next question, where should the outlet be for an EV? Front of the vehicle, or the back?

 

[ning]

I'm seeing recommendations about for 50A, but if you're trying to future-proof I'd install wiring at least a couple sizes bigger.
Maybe just run the wires to a box with a full cover, don't bother with a plug which may need to be swapped out later.
For that matter, you could even leave out the breaker for now, just have the wires capped in the panel with a tag on them, run through the wall. The savings on the "just guessing the size" on the breaker & plug should pay for extra copper and then whoever actually installs the charger can pick exactly what's needed.

Considering how long a car may be plugged in for that, I'd try to set up the garage subpanel has 100A, too.

 

[workinonit]

Eddie, charging those things isn't magic. For the fast chargers it probably takes at least a 70 amp circuit if not more. I think the slow chargers can be run from a 120 V outlet.

 

[Minsid]

I recently went through the same thinking and just went with 50A figuring that'd be enough to charge anything overnight. I'd probably not be looking for a super fast charge at home. 50A is also usable for the welder.

The charge ports are currently toward the back but thats easily changed by model.

 

[ning]

I think the standard for a "fast charger" is 48A continuous, which requires a 60A circuit minimum.

 

[MapleLeafFarmer]

depends on a lot of factors like type of battery in your vehicle, how fast you want it to charge etc.... but...

on my F150 with an extended range battery from empty:

15a breaker @ 120v is a level 1 charger, slow, will take about 80hrs to charge my extended range battery on F150

40a breaker @ 240v is considered a level 2 charger but on the slower side, same truck, about 16 hrs

80a breaker @ 240v is also a level 2 charger and what is considered the big one, about 8hrs

most level 2 charges (240v) you buy are switchable to match what size breaker is being used.

level 3 chargers (like the Tesla super chargers) are much much faster and considered DC chargers not something I would think any homeowner would every foot the bill for. Cost for these are $200 or more depending on your access to the grid.

don't forget if you are looking into the future you may want to plumb for more than one charger as most of us have more than 1 vehicle in our garages and you don't want fights on who gets to charge overnight and who wakes up in the morning empty and cold. Although you being in Texas I doubt heating your interior is a concern but battery will use power keeping batteries cool if left in the sun and hot.

some of the smaller cars (also the cheaper ones) would could charge 2x as fast as their battery size is probably much less but no first hand experience to share.

edit: My charger was configurable @240v for as little as 20a up to 80a configured at time of installation.

 

[civilian]

Is it better to have the charging station outside, away from the garage and house in case of fire? Jon

 

[ultrarunner]

Can you swing a 100amp sub panel?

Compressor, welder, chargers???

If cost a factor maybe just foresight in sizing conduit?

 

[ponytug]

I would plan on at least one 80A circuit. While there are some Level 2 chargers can do 20kW, (83A, aka more than 100A breaker), most cars and trucks will get a full charge on 60A overnight, and not every car can take in 20kW. The second question would be what are the chance you might be using two EVs? (X2 on the 80A circuits...)

Put another way, what is the likelihood that you and your wife would routinely both drive more than 250 miles in day?

All the best,

Peter

 

[MapleLeafFarmer]

Can you swing a 100amp sub panel?

Compressor, welder, chargers???

If cost a factor maybe just foresight in sizing conduit?

one 100amp breaker for each ev vehicle you own is what Ford recommends for their F150 charger.

 

[ultrarunner]

Should keep electricians in business for years in my city.

I manage single family homes in the 600k to 2m range and the largest service is 150 amp… and the smallest is 30 amp 120v.

The majority range from 60 amp 240v to 100 amp 240v.

Transformers are going out and being replaced all the time… utility crew changing another right now 300 yds away.

Couple that with the mandate for all electric and it is what it is.

 

[fatjay]

You guys are nuts.

I never planned to buy an ev either. Until I did. I didn't even have a charger for it. I quickly ordered on on amazon that is level 1 and 2, 110v and 220v. I plugged it into a 110v and set it to 8a. And I just leave it charge over night or any time I'm not using it. It's a bit on the slow side, but soon I'll be bumping it up to 220v 16a, so 4x charging, which is plenty fast for just an overnight charge.

Slow charging batteries extend the life of the batteries. I wouldn't fast charge it if I didn't have to.

 

[Spanky100]

I think the standard for a "fast charger" is 48A continuous, which requires a 60A circuit minimum.

ning is correct for level 2 direct wired chargers supplying 11.5 kW/48A charge rate max (220Vac) use at least a 60 amp breaker and associated circuit wiring.

The National Electric Code (NEC) requires that dedicated breakers supplying EV Chargers be rated for at least 125 percent of the maximum EV charge rate

Level 2 residential chargers are currently most common from what I have seen for those that charge at home. As larger vehicles and battery capacity increases over time I suspect the push will be on for more charging current capacity to decrease charge time.

Our EV has a 63 kW battery and at 95 percent depleted battery it will easily charge overnight (less than 8 hours at 11.5kW/48A).

Most current homes I have seen were built with 100 to 200 Amp service/panel so at some point that will be the limiting factor unless money is spent for upgrade service/panel entry. We have a 150 AMP main panel that could have been upgraded to a 200 AMP panel to align with the 200 service from power company. After reviewing our other electrical needs, the electrician confirmed we did not need to upgrade panel. Which would been and additional cost.


Our circuit has a 60 amp dedicated breaker allowing us to charge at 11.5 kW/48A max charge. We had an Emporia Brand Level 2 EV Charger direct wired into the end termination box. Direct wiring the Emporia Charger allows us to use a settable (thru phone app and charger wifi connection) from 6 Amps to the maximum 48A/11.5kW). If we chose to have the a NEMA 14-50P plug in the outlet box installed we would have been limited to 40A max charge. The Emporia Charger came with the mating 4 prong connector hookup that would connect to a NEMA 14-50P plug. That cord and plug could/was removed to allow the direct wiring from the breaker/wire circuit directly into the charger terminal box. We chose the direct connection for two reasons 1) allows max charge rate capability and 2) over time the receptical/plug can generate heat if the prong clamp load lessons.

side note
We placed the direct wired charger on the inside wall of the garage between the two garage doors. This was so we could charge in either of the two garage bays inside or outside of the garage with the 24 foot charger cable.

Spanky

 

[EddieWalker]

Thank you for all your replies. Since I don't have any plans to buy an EV at this time, I'm really just wanting to run the wires that are big enough to handle and EV if it ever happens.

Lowes has 2-2-2-4 USE Aluminum for just under $4 a foot. Is there any reason not to use this? It's bigger then what I think I need. I'll just put a 50 amp breaker on it for now, and if I ever buy a UV, I can swap out the breaker for what I need, up to 100 amps.

https://www.lowes.com/pd/Southwire-2-2-2-4-Black-Stranded-Al-MHF-Use-2-Cable/5002300757

 

[ericm979]

I think the standard for a "fast charger" is 48A continuous, which requires a 60A circuit minimum.

This brings up a good point- EV charger circuits need to have derated breakers- the breaker is smaller than the wire capacity. Where welders can have uprated breakers. It's because the charger's demands are continuous but the welder is intermittent.

I didn't understand this when I had "welder/EV" wiring added to the garage. It's on a 50a breaker but I don't know if that's welder 50a or EV 50a. If it's welder 50a that might be about 30a for a charger. The wire's super thick and the electrician complained about how hard it was to deal with so maybe it's EV 50a.

Another mistake was to spec a 6-50 plug. Welders use that, and back then about half the chargers did, but now chargers seem to use 14-50. My wife still hasn't found an EV she likes so it only got used for welding.bb

 

[EddieWalker]

I'm still in the thinking stage on this. My current thought is to put the EV outlet box in the small 2 foot wall between the garage doors. I can go to the other wall, but that's where we have our refrigerators, and the walkway through the garage is between the front of the cars, and the refrigerators.

For the box, does it make sense to cut the wires and wire nut them together, or try to create a loop inside the box so I can cut them in the future if I buy a EV? I have no plans to put an outlet in at this time, I just want the wire there in case we buy one.

My concern with not cutting them is having enough wire to work with when I buy an outlet. I don't think I can bend and twist it enough to fit into a double box, and still have enough to work with.

Any issue with wire nuts for this, or is there something better for the long term that it might remain like this?

 

[ponytug]

I'm still in the thinking stage on this. My current thought is to put the EV outlet box in the small 2 foot wall between the garage doors. I can go to the other wall, but that's where we have our refrigerators, and the walkway through the garage is between the front of the cars, and the refrigerators.

For the box, does it make sense to cut the wires and wire nut them together, or try to create a loop inside the box so I can cut them in the future if I buy a EV? I have no plans to put an outlet in at this time, I just want the wire there in case we buy one.

My concern with not cutting them is having enough wire to work with when I buy an outlet. I don't think I can bend and twist it enough to fit into a double box, and still have enough to work with.

Any issue with wire nuts for this, or is there something better for the long term that it might remain like this?

If it were me, I would pull the wires and terminate with a 14-50 outlet. As @fatjay mentioned, that is now the common standard, and if you decide later to go with a wired charger, which I think is preferable, you should be ok. If the electrician wires the plug on the short side, there are always Polaris connectors.

I am not an electrician, but I think that 2ga aluminum (72A ampacity @60C, while copper is 95A @ 2ga) is pretty light for what you are proposing. Even 6kW over 2ga is a substantial voltage (and power loss). I would go heavier gauge, and go for copper if you can find burial rated copper in your area. Locally, I can only get it from electrical supply houses. I would set it up for 200A service and be ready. EVs consume much more power and for much longer periods of time than any other home load.

All the best,

Peter

 

[MapleLeafFarmer]

Thank you for all your replies. Since I don't have any plans to buy an EV at this time, I'm really just wanting to run the wires that are big enough to handle and EV if it ever happens.

Lowes has 2-2-2-4 USE Aluminum for just under $4 a foot. Is there any reason not to use this? It's bigger then what I think I need. I'll just put a 50 amp breaker on it for now, and if I ever buy a UV, I can swap out the breaker for what I need, up to 100 amps.

https://www.lowes.com/pd/Southwire-2-2-2-4-Black-Stranded-Al-MHF-Use-2-Cable/5002300757

nope not suitable for the chargers I have experience with. Installation say alum. a no go.

Not supposed to use alum. wire as the charger is both a continuous use of high power (many hours) and regular use (very often)
ie: to much power to often but service drops are the same IMHO but its what the installation manual said.
but 2-2-4 alum. USE-2 / URD from Southwire is rated 165 amps when buried though??? so I'm clueless only sharing what installers book said.

 

[EddieWalker]

Thanks. Aluminum would of been a lot cheaper. But I understand how much better copper is. I just hate paying for it!!!

If it wasn't your money, what size copper wire would be ideal to run?

 

[Spanky100]

I'm still in the thinking stage on this. My current thought is to put the EV outlet box in the small 2 foot wall between the garage doors. I can go to the other wall, but that's where we have our refrigerators, and the walkway through the garage is between the front of the cars, and the refrigerators.

For the box, does it make sense to cut the wires and wire nut them together, or try to create a loop inside the box so I can cut them in the future if I buy a EV? I have no plans to put an outlet in at this time, I just want the wire there in case we buy one.

My concern with not cutting them is having enough wire to work with when I buy an outlet. I don't think I can bend and twist it enough to fit into a double box, and still have enough to work with.

Any issue with wire nuts for this, or is there something better for the long term that it might remain like this?

Eddie

I would suggest leaving excess length wires with a cover plate over it in the metal box where the charger is to mounted. This way if you get an EV you can either install a NEMA receptacle in the box or direct wire to the charger. In our case the steel box (i think 4 inches square) is about 8 inches from the charger. We used flex steel conduit to encase the wiring from the box to the EV Charger. When selecting a location make sure there is room for the EV Charger to mount. We had room between out two garage doors so it worked well.

I will try to get a picture of the receptacle box and EV Charger on the wall to show the setup.

Spanky