Garage EVSE build question

[cossie1600]

I currently have a 40A circuit running into one side of my garage off a 100A subpanel. Since I have two cars that can handle 10kwh charging, I am going to break down and install a 50A circuit on the other side of the garage. The new circuit would come directly from the 200A main panel on the other side of the garage wall, so a very short run. My question is, should I go crazy and build a 100A circuit and run a 2 gauge wire in case I decide to get a Tesla. Or should I just install a 6 gauge wire with a 50A circuit. Also with the 50A circuit, should I install a 6-50R or 14-50R outlet?

I am going to keep the other circuit, but might try to sell my GE 40A EVSE if I can get any money for it.

 

[miimura]

Go as big as you can. However, I think when an electrician does the load calcs, you may not be able to add a 100A breaker to a 200A panel.

 

[smkettner]

I thought Tesla was moving away from dual chargers.

I honestly would be going just 40a circuit and 30 or 32 amp charging. Sometimes I think running at max could contribute to some charger failures.
I am doing just fine with my 30 amp Schneider.

Nothing wrong with #6 wire in the mean time.

 

[fromport]

I thought Tesla was moving away from dual chargers.

I honestly would be going just 40a circuit and 30 or 32 amp charging. Sometimes I think running at max could contribute to some charger failures.
I am doing just fine with my 30 amp Schneider.

Nothing wrong with #6 wire in the mean time.

12 of the same units that are in our cars makes up one tesla supercharger.
I think our built in chargers can do the 40 amps easily. I think it will actually go to up to 270 volt ac, but it will probably cut down the amps to less than 40 ;-)
I feel very confident charging at 40 amps.
I would install a 50 amp circuit (breakers) with #6 wire to charge at 40 amps.
If you want to charge faster, get the Jdemo (always handy enroute) and get a home chademo charger ;-)

 

[JasonA]

It depends on the city and code but they did it with mine. I had a new 200a main when the 10kw array was installed back in 2013.

80a breaker going a Siemens 70a Versicharger (rare but I used to work for Siemens power).. this is 4ga.

60a breaker going to the garage for the OpenEVSE beast (aka 277v boosted) this is 6ga.

No problemo.. Here's the guys charging at my house...

The Silver Tesla (Mr.GID) is getting 277v/40a and the Red Tesla is getting 240v/70a

And the array is pumping out ALOT

P.S. The onboard charger will put out 11kw max at 277v... it works the best at higher voltages! The more voltage you give it, the less amperage it draws.

277v and its only pulling 38a avg. Remember you're only getting 9.8k at 240v.. and that's IF YOU HAVE 240v at full 40a. Watch it drop!

265-277v is the way to go!

 

[fromport]

No problemo.. Here's the guys charging at my house...
The Silver Tesla (Mr.GID) is getting 277v/40a and the Red Tesla is getting 240v/70a
And the array is pumping out ALOT
P.S. The onboard charger will put out 11kw max at 277v... it works the best at higher voltages! The more voltage you give it, the less amperage it draws.
277v and its only pulling 38a avg. Remember you're only getting 9.8k at 240v.. and that's IF YOU HAVE 240v at full 40a. Watch it drop!
265-277v is the way to go!

Awesome photo's ,
Awesome info!

Thank you !

 

[cossie1600]

I spoke to the electrician. I can do a 50amp circuit with a 6AWG or pay $85 more to go 4AWG for a 60A. Is that necessary since most cars can't do more than 10 in the foreseeable future?

I already have a 8AWG 40A on my other side of the garage. I just want faster services since both of my cars can handle 40a charging instead of just 32a

The electrician said I might be able to install a 2AWG on a separate on/off switch and make it future proof by adding the 100A service in there.

 

[JasonA]

Depends if you're going to be getting a MS with dual chargers. If not, there's nothing else that's going to have over 10kw or 40a constant requirements.

But you said "in case I get a Tesla" and there are TONS of CPO's out there and most seem to have dual chargers already :shock:

I'm looking at 2 right now actually

And I agree with miimura-- if you can afford it.. Go Big!

Less loss too!