How many Amps to charge an EV?

[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.

Loading…

www.lowes.com

 

[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.

Loading…

www.lowes.com

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