Adding home EV charging ?s

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EbS-P

Minister of Fire
Jan 19, 2019
6,050
SE North Carolina
It is likely that I will be getting a Tesla In January. I have been debating the best way to add at home charging to my home. Should I go the cheapest route now and just at a single 120v 20 amp outlet? Is 120v charging even a option I should consider or should I plan for the future of more than 1 EV and run a circuit capable of charging multiple EVs at once. Should I consider a Tesla wall charger to the tune of 550$. What would you do?

Relevant Details

No garage

Lots of kids oldest is 10

200 amp service entrance at back of house opposite where we will be parking in the front of the house

1 unused 30A double pole breakers in main box. (It fed a water heater) and the wire runs about to middle of house through crawl space

Exterior 70A subpannel (right next to main) with open spots
One exterior 15 A outlet on front porch

One 20A single pole unused in interior sub panel (does not have any empty spots) with wire running to corner of house nearest where we will park.

Driving mileage is about 100-150 miles a week.

Thanks in advance for any feedback
Evan
 
Tesla states 2 to 4 miles per hour of charge with 120 VAC 20 Amp charger. So assuming you have 12 hours of charging overnight, that is 24 to 48 miles per night. So spread your miles over 7 days and you have potential range of 168 to 336 miles per week which meets your requirements. That said take one long trip on a weekend and you may be short overnight charging. I have Rav 4 Hybrid so all I do is buy some gas but with your Tesla you are out of luck.

The 30 AMP dual pole breaker is going to give you double the charge. over night.

Looks like 240 @50 Amps is the largest charge rate, 30 miles per, hour so running a dedicated circuit to the driveway from the 70 Amp to the sub panel is the fastest option. If you are paying an electrician to do the work, my guess is the 50 Amp circuit from the main will not be that much more expensive than extending the 30 Amp circuit.

Keep in mind there is federal tax credit, It covers 30% of the costs with a maximum $1,000 credit, and there may be other state local and utility credits to reduce the cost further. Make sure that you also check to see if there are any special rates for charging EVs (whihc may require a separate meter).
 
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Based on our experience using both 120VAC 15A and 240VAC 50A circuits for charging, I wouldn't go with anything smaller than the latter.
You'd probably be surprised how many times you'll plug the car in to charge only to unplug 30 min. later when you want to take an unplanned trip.
I'd also consider installing an SAE 1772 EVSE and using an adapter rather than installing a dedicated Tesla EVSE.
Running the circuit out of the subpanel seems to be your easiest option if you go 50 AMP or more.
Consider also that you can either hardwire the EVSE or install a standard receptacle and plug in the EVSE using a pigtail. A NEMA 14-50 is a standard electric dryer outlet and can be used for RVs , welders, etc.
Our EVSE is connected using a plug and a NEMA 14-50 and is also quickly detachable that we can take it on trips if needed. This allows us to plug the EVSE into a dryer outlet at remote locations (e.g. family/friends) for charging.
 
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240VAC 50A circuits for charging, I wouldn't go with anything smaller than the latter.
I agree that this is the best solution.

While we are pretty environmentally conscious getting an EV just never was a reality for us. We will soon be a family of 7. My work schedule really only has me out for 4-5 hours max 4 days a week working from home the rest.

So if want to change 3 EVs what should i be running? Probably a separate 60-80 amp sub panel? I think this is a reality for us in the next decade.

I am only 2.5 miles from a super charging station. So that is kinda figuring into my thoughts process.

I have access to the basement ceiling and rim joist now in the area the wiring will penetrate so I’m not opposed to future proofing so I don’t have to pull drywall later.
 
If 240V and 50A is too much (e.g. if you want three independent circuits), then I think 240V and 30A or even 240V and 20A is fine. The 20A example is 16A continuous duty (80% rating), and 240Vx16A = 4 kW. This is still 3-4x faster than 120V and 10-12A. 240V and 30A is 24A continuous, which is 6 kW, which will charge a Tesla from empty in 12 hours or so.

There are also EVSEs that have two heads and they will sequencially charge two EVs from a single circuit. Never seen on in the wild.

I charged my 60 kWh Bolt EV for year at 6 kW and it was never a problem.

I agree that 120V charging is a JOKE and not worth the effort to set up.

One thing to remember: 120V charging is often less efficient that 240V charging, bc the EVSE is set up to use 240. Add something like 10% to the cost to charge.

My buddy just upgraded from a LEAF Gen2 to a Model 3, and he is just gonna use the portable with the 50A outlet.
 
Which Tesla model are you looking at? The reason I ask is the standard range Model 3 can only charge up to 32A or a 40A breaker. That being said I would be tempted to install the Tesla charger, as it can accept up to a 60A breaker for 48A of continuous charging.

The other reason to go with the Tesla charger is they have added functionality to share load between up to 4 chargers, so you could program it to split the power off a 100amp panel between 3 vehicles, which would allow a full 48 amps to a vehicle if only 1 was plugged in or would split the power to 3 vehicles at 26.6 amps each. I believe you can go up to a total of 190 amps between all 4 chargers.

 
I agree that this is the best solution.

While we are pretty environmentally conscious getting an EV just never was a reality for us. We will soon be a family of 7. My work schedule really only has me out for 4-5 hours max 4 days a week working from home the rest.

So if want to change 3 EVs what should i be running? Probably a separate 60-80 amp sub panel? I think this is a reality for us in the next decade.

I am only 2.5 miles from a super charging station. So that is kinda figuring into my thoughts process.

I have access to the basement ceiling and rim joist now in the area the wiring will penetrate so I’m not opposed to future proofing so I don’t have to pull drywall later.
While you have access I think that installing another (maybe 100 amp) subpanel near where your EVSEs will be installed would make sense. While you may not have the capacity in your existing main panel for a 100 amp breaker I believe the building code is okay with using a smaller breaker to feed into a larger subpanel - maybe 50 A for now. This might be upsized later if you need more EV charging capacity and your main panel can handle it.
It seems also that if that many EVs are in your future you may need to upgrade the capacity of your service drop and/or add another main panel -- maybe... That would all depend on how many EVs you need to charge at once and whether you go with something like the Tesla shared EVSE that @ABMax24 mentioned.
 
Which Tesla model are you looking at? The reason I ask is the standard range Model 3 can only charge up to 32A or a 40A breaker. That being said I would be tempted to install the Tesla charger, as it can accept up to a 60A breaker for 48A of continuous charging.

The other reason to go with the Tesla charger is they have added functionality to share load between up to 4 chargers, so you could program it to split the power off a 100amp panel between 3 vehicles, which would allow a full 48 amps to a vehicle if only 1 was plugged in or would split the power to 3 vehicles at 26.6 amps each. I believe you can go up to a total of 190 amps between all 4 chargers.

Very good info. It will be a used X. At 500$ a wall charger man that’s more than a years worth of charging for me. Seems like limiting charging rate per vehicle at the vehicle interface would save lots of money.

It kinda feels like that once you choose Tesla it becomes much more unlikely that you will choose an EV from another manufacturer. Kinda feels like apple. Once you have two apple devices you are too far in to the unified ecosystem to jump ship to android or PC.

Making a plan for multiple Tesla wall chargers makes since.
While you have access I think that installing another (maybe 100 amp) subpanel near where your EVSEs will be installed would make sense. While you may not have the capacity in your existing main panel for a 100 amp breaker
Yep. That’s the answer pull heavy enough wire to run a 100A panel with what ever breaker I can fit. now and deal with main panel modifications at which ever time.
 
You can put in multiple 240V plugs at say 30A breakers, use the Tesla portable charger and still happily charge EVs from other makes on the other outlets. No lock in.

Use case: you might buy a cheap EV for a teen driver. Not gonna put a teen in a Tesla
 
Very good info. It will be a used X. At 500$ a wall charger man that’s more than a years worth of charging for me. Seems like limiting charging rate per vehicle at the vehicle interface would save lots of money.

It kinda feels like that once you choose Tesla it becomes much more unlikely that you will choose an EV from another manufacturer. Kinda feels like apple. Once you have two apple devices you are too far in to the unified ecosystem to jump ship to android or PC.

Making a plan for multiple Tesla wall chargers makes since.

I do agree that Tesla is much like Apple, they want to be the only provider of service and accessories for their vehicles. Unfortunately though today there isn't a whole lot of choice, no other car maker comes close to the Tesla's capabilities.
 
I do agree that Tesla is much like Apple, they want to be the only provider of service and accessories for their vehicles. Unfortunately though today there isn't a whole lot of choice, no other car maker comes close to the Tesla's capabilities.
I agree their integrated products are the best but that’s comes with limitations like the nearest service center being two hours away.
 
I agree their integrated products are the best but that’s comes with limitations like the nearest service center being two hours away.

That's not terrible, up here the nearest supercharger is 5hrs away, and the service center is also 5hrs away.

Safe to say I'm not looking for an EV just yet.
 
You can put in multiple 240V plugs at say 30A breakers, use the Tesla portable charger and still happily charge EVs from other makes on the other outlets. No lock in.

Use case: you might buy a cheap EV for a teen driver. Not gonna put a teen in a Tesla
That’s what I’m trying to plan for future proofing. I wonder what the market will be for 10 year old Tesla 3s. Being able to record yours teens driving footage is an interesting concept. Safety wise I think they have a good safety record. Collision avoidance is a selling point. I can’t believe my parents let me drive a 63 MG midget for a year as my to and from school /store car. I did graduate up to a 1982 Volvo 240DL from the MG. But my mom got the car with air bags. Argument has been made you should put the most inexperienced drive in the safest car.
 
That's not terrible, up here the nearest supercharger is 5hrs away, and the service center is also 5hrs away.

Safe to say I'm not looking for an EV just yet.
Agreed. I was looking this is just too good a deal to pass up.
 
Unless you regularly are maxing out your charge range, I think a 240V/20A circuit is very adequate for a Tesla, and with an adapter will also be good for other EVs that take a J1772 plug. We have a Tesla Model 3, Dual Motor, AWD. Charging is from a 20A-240V circuit in our garage. Outlet is a standard L5-20R which we had in our garage, and we have a 16A EVSE with L5-20P to J1772 and adapter to the Tesla plug. If you need to install a sub-panel in your garage, 100A would be adequate for up to 5 20A circuits or two 40A circuits or one 40A circuit and two 20A circuits.

We usually charge to 240 miles, which is very generous for daily driving needs. This is my wife's car, and when she's home for the day she plugs in to the Tesla and the car is always ready to go in the morning for the next day needs. We may travel 2-3 times/month to visit family in Minneapolis/St.Paul, distance 180 miles, we also have two Tesla Super Chargers on the route, one 40 miles from our home and the other 115 miles from our home, and also several Super Charging stations in the metro area to charge as needed for driving in the metro area and the return trip home. Tesla also has two service centers in the metro area.

And we have have Tesla Mobile Service available, which we have used once for a recall to check the shoulder belts bolts (no charge), and for which we have now scheduled for a brake service check/lubrication and cabin filter replacement. We have had the Tesla nearly three years (32,000 miles), and this is the only service the Tesla has required.
 
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First off, congrats on your upcoming EV purchase. We got a Leaf a couple years ago and love it; two pleasant surprises, fast as hell (and I can only imagine what a Tesla would be like) and virtually zero maintenance. I plan to keep my '06 Subaru Outback going a few more years and then hopefully available vehicle range and charging infratsructure will make it possible to live without an ICE vehicle and I'll buy a Cybertruck or something.

I'll join the chorus here saying to forget about relying on a 120vac charging circuit.

As far as using your existing 240vac/30amp circuit, do they even make EVSEs that work off that low an amperage ? I installed a 40amp Clipper Creek unit (with a 50amp breaker and 8awg wire in conduit) for a little future-proofing even though the Leaf can only handle 32 amps. If you do your own install, be aware you can generally use lighter-gauge wire if you put it in conduit (and conduit is fun).

Finally, @semipro suggested installing a standard 220vac receptacle and plugging into that. I briefly considered that before realizing that left me with two poor choices: leave the portable charging cord plugged into the receptacle at home and thus have no way of charging away from home (e.g. at a friend's house) or plug that portable cord in to the receptacle whenever I get home. Not only would the latter be a hassle, but every time I connect my car to the hard-wired EVSE in the rain, I thank my stars that I did it this way; of course, if you'd be in a garage, that might not apply.
 
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Not only would the latter be a hassle, but every time I connect my car to the hard-wired EVSE in the rain,
It will be outside. That is a good point.
two poor choices: leave the portable charging cord plugged into the receptacle at home and thus have no way of charging away from home (e.g. at a friend's house) or plug that portable cord in to the receptacle whenever I get home.
And another….
 
Meh. Used 240V 16A portable EVSEs can be had CHEAP. You can have one in your trunk AND in your garage. I have a couple extra sitting in my garage right now. And they're fast enough for nearly every EV need (at 4kW). No need to spend >$500 for a fancy unit any more.

Many new ones on amazon for $200: Amazon product ASIN B08KNWPRWJ
Or $130+shipping new on EBay: https://www.ebay.com/itm/124915062325?hash=item1d15849635:g:gIgAAOSws~phFpej

Note, these are 120V/240V dual voltage units. Many of the 120V units shipped with EVs can be used at 240V and 16A, read the label.

My friends with a tesla have said that fender benders can be expensive.... all those sensors can be damaged with a new driver in a low speed impact or scrape. And then they need to be replaced and recalibrated a service center. I can find a safe non-Tesla EV for my teen drivers (who learned on a 2014 LEAF and a 2015 Volt, respectively). Both vehicles had some cosmetic dinging from the experience.
 
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I am happily charging my Bolt on a 240V/20A circuit using a TurboCord. It provides about 3.3 kW/h. I used to use a 240V/40A charger and it was faster (for overnight rate charging) and that was nice, but a lot can be said for getting started (inexpensively) with a 3.3 kW/h charger.

Depending on the length of the wiring run, you may want to price out the copper cable for the charger before you make a decision. 50A rated cable is running about $4/ft right now (per my electrician).
 
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Finally, @semipro suggested installing a standard 220vac receptacle and plugging into that. I briefly considered that before realizing that left me with two poor choices: leave the portable charging cord plugged into the receptacle at home and thus have no way of charging away from home (e.g. at a friend's house) or plug that portable cord in to the receptacle whenever I get home. Not only would the latter be a hassle, but every time I connect my car to the hard-wired EVSE in the rain, I thank my stars that I did it this way; of course, if you'd be in a garage, that might not apply.
Yeah, mine is located out of the weather. That said, I have yet to unplug/plug it to take the EVSE with me for remote charging but it's a nice option should I chose to do so. My 50 amp oulet is weather protected and GFCI (by code) also so not a big safety concern.
Adding home EV charging  ?s
 
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All you guys saying that the lower power EVSEs are workable must be much better planners than my wife and me. At least weekly I'm thankful for the faster charging our unit provides. My wife comes home from work in the BEV and then we decide we want to go somewhere in it.
I can only imagine that if @EbS-P actually has 3 BEVs in the driveway that the one with the most charge will be the one next taken.
 
And we have have Tesla Mobile Service available, which we have used once for a recall to check the shoulder belts bolts (no charge), and for which we have now scheduled for a brake service check/lubrication and cabin filter replacement. We have had the Tesla nearly three years (32,000 miles), and this is the only service the Tesla has required.
It's really interesting how Tesla is redefining vehicle purchasing, ownership, maintenance, and mobility. The similarities to smartphones are many -- ownership/leasing, not easily replaceable batteries, over-the-air feature/security updates, restricted serviceability, packed with sensors, etc.
 
All you guys saying that the lower power EVSEs are workable must be much better planners than my wife and me. At least weekly I'm thankful for the faster charging our unit provides. My wife comes home from work in the BEV and then we decide we want to go somewhere in it.
I can only imagine that if @EbS-P actually has 3 BEVs in the driveway that the one with the most charge will be the one next taken.
It just comes down to if the BEV has enough range for your daily driving. If so, 4kW overnight is close to 50 kWh, or 150-200 miles. Do you often drive >150 miles per day in a BEV without it being a roadtrip? If so, then DO upgrade to a higher power EVSE. Otherwise 4 kW is pretty OK.

OP's plan of one higher power, and two smaller seems like a good one.
 
I didn't read the entire thread (a lot of quick interest from the crowd!), but your "no garage" comment made me think of a car port. I read that a solar car port benefits from the 26% tax credit. I'm pondering the feasibility of this for the house, even though I don't yet have an EV.
 
It's really interesting how Tesla is redefining vehicle purchasing, ownership, maintenance, and mobility. The similarities to smartphones are many -- ownership/leasing, not easily replaceable batteries, over-the-air feature/security updates, restricted serviceability, packed with sensors, etc.
I’m not super keen on that. I’m not a gear head or an auto enthusiast but I like the idea of some aspects of being to maintain my own vehicl (and phone). First car was an MG that says a lot. Its Really not replacing a vehicle either. We every summer drive 600-1000 miles in a day, two to four days a year. Kids all fall asleep you don’t dare stop that car;). So if the batterys not charged i would have options. i almost have the mini van paid off and the lifetime warranty they sold me 4 days after the third baby arrived (a couple weeks early) I am bound and determined to get every cent i can out of that company.