80 amp residential E.V.
- Thread starter nizak
- Start date
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
MOstly we see 60 amp units
AC\DC
Senior Member
- Location
- Florence,Oregon,Lane
- Occupation
- EC
Why would you need that big of one at your home you street racing at night
marmathsen
Senior Member
- Location
- Seattle, Washington ...ish
- Occupation
- Electrical Contractor
Earlier models of the Tesla Wall Connector were capable of being supplied by 100A. We installed some of those. Required copper wiring so we piped it the whole way.
Rob G - Seattle
Concerned with effects the load it might have on the transformer serving the residence.
It’s in a subdivision. I don’t know how many other homes are being supplied by the transformer or the size of it.
The house itself has a 320A service.
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
Local POCO here are now requiring notification and load calculations whenever installing EV loads. With a warning that if you don't and it overloads the transformer you will pay for the cost to replace. The issue here is we already have way too many transformers already sitting on the edge of failure, from just from "normal" loads being added across the system.
Being in a subdivision I would suspect there could be as many as 4 houses on the one transformer.
I would be less concerned if it was a single feed residence and I could see at least a 25KW xmfr sitting there.
Did you add that to your existing service or did you need to upgrade ?
tallgirl
Senior Member
- Location
- Glendale, WI
- Occupation
- Controls Systems firmware engineer
Because EV battery sizes are getting insane?
You can do the math - 100kWh battery, 8 hours, assume 100% efficiency is 12.5kW, that’s 50A-ish.
Just my opinion, I could be wrong, but no one needs a 50A charger unless they are running a taxi or delivery business out of their house and are actually driving 300 miles a day.
No. It was added to my existing 200A service. My home has gas heat and hot water.
I highly doubt you’ll have any issues adding one to a 320A service, but doing a load calc would be a good idea.
We’ve discussed many times on these forums how overly conservative NEC load calcs are.
About the only new 80A units out there today are the ones that came standard with 2022 and 2023 F150 Lightnings with extended range battery (131 useable KwH). That’s why I have one. Otherwise there’s no way I’d buy one that large. It’s really overkill. I rarely use it at 80A, I normally charge at 48A, but it’s nice to have it available. When I get home from a road trip at a relatively low state of charge, it’s nice to get it back up quickly if I need to go again. That’s happened maybe 5 times in the almost 2 years of owning it.
As of the 2024 model year, the Lightning’s max charge rate is 48A. The 80A charge rate capability and EVSE are only offered to fleet customers.
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
Around here, 15’s are the norm for a single house.
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tallgirl
Senior Member
- Location
- Glendale, WI
- Occupation
- Controls Systems firmware engineer
Yes, but EVSEs are the biggest load to be added to homes since tankless water heaters and I'd like to look at 1 minute resolution load data from a home with both.
So you did wire it for the 80 amp capability and generally charge at 48?
That’s one of my unknowns with the EVSE the customer is getting.
I would assume it has the ability to charge at lesser rates even when installed a s a 80 amp output on a 100A breaker.
It’s a long convoluted run from the panel to the equipment. About 130’ when all said and done.
There’s quite a difference in install cost between the 100A and 60 A wiring and associated components.
Interesting combination, for sure.
And having the AC condenser start simultaneously would only make that number more interesting
tallgirl
Senior Member
- Location
- Glendale, WI
- Occupation
- Controls Systems firmware engineer
I looked at AC condenser inrush versus run current ages ago. I'm not nearly as concerned about that as someone coming home from a long day, plugging in their Giant Mega EV, and taking a 10 minute shower with the tankless heater going.
But yes, with smart thermostats turning on the AC when Giant Mega EV owner comes home and takes their shower, it's a plausible scenario.