Home EV charging

[RetMD21]

I don't plan to be needing more than a small part of my range on the average day and I am wondering what would be the best arrangement. The 48 amp hardwired EVSE seems to be more than I need. I could use a lower amp plug in solution but I have heard about melted receptacles. I'll contact an electrician but I want to be an informed consumer. What are people using?

 

[REWahoo]

I don't plan to be needing more than a small part of my range on the average day and I am wondering what would be the best arrangement. The 48 amp hardwired EVSE seems to be more than I need. I could use a lower amp plug in solution but I have heard about melted receptacles. I'll contact an electrician but I want to be an informed consumer. What are people using?

I've been using a plug-in EVSE (Emporia) for several months after the EVSE that came with my Bolt failed (the unit, not the plug).

The advantage of going plug-in vs hard wired is that if your EVSE ever fails, as my first one did, you won't need to pay an electrician to install a replacement. With a plug-in you can charge at a rate of up to 40 amps but I rarely go that high as 32 amps works great for us.

As long as your electrician does a quality install using the proper size wiring and a commercial grade 14-50r receptacle (Hubbell or Bryant brand) you will have no issues with the plug/receptacle overheating. FYI, the Bryant is made by Hubbell, is virtually identical and costs less.

Edit to add: Charging at 32A my plug/receptacle is barely warm to the touch, even after several hours of charging.

 

[OldShooter]

On something like that I automatically select the most capable solution since I don't want to be tearing out an inadequate one and replacing it with a more capable one if I change cars. This strategy doesn't even consider the requirements of the current car.

It is a corollary to the "Do not buy cheap tools." rule.

YMMV of course.

 

[Alan]

The home charger we have is a 30amp charger at 240v, so charges at 7.2kW. It is a smart charger controllable by an app to set schedules such as “Charge to 80% by 05:30”. It also integrates with our energy supplier and will charge the car during the cheapest overnight periods, but never above 7.5p/kWh. It also communicates with the solar panel inverter so if plugged in during the day it will route excess solar power to the car rather than export it back to the grid.

 

[perez99]

I have a 48amp hardwire charger (so 60 amp breaker), but usually charge at a lower rate 40 amp rate as there is no cost advantage from my utility on time.

I would go with the max amp charger you can setup. You never know when you need faster charge.

 

[aja8888]

I have an Emporia charger like REWhoo and it's pretty nice. It requires a 240 V line and you can set the rate of charge in the software on your phone.

Until I got GM to install the 240 volt circuit (free up to $1,250.00 cost), I charged with the 120 Volt charger that came with the car @ 12 amps. That worked fine and it would charge at a rate that was acceptable for daily use.

 

[audreyh1]

We have the Tesla Wall Charger, but before that we used the Tesla Mobile Connector plugged into our 50A RV pedestal. That charged at 32A giving us ~7.4kW, certainly a decent rate for home charging. The Tesla Wall Charger is capable of charging at 48A. We have ours set at 40A and now charge at 9.6kW, almost 10% an hour, plenty fast.

The Tesla Wall Charger has many built in safety features including overheat detection.

 

[Luvtoride]

RetMD, what type of EV are you purchasing? For our two Tesla's we have a Chargepoint Flex, level two charger installed at 50 AMPS. It was hard wired into my electrical box by a qualified electrician with permits and inspection by our town and our utility. In NJ, PSEG, covered 100% of the installation charge, including permits for the charger and offers off-peak charging discounts after 9pm.
It charges at 40 amps which translates to about 35+ miles per hour.

I would definitely recommend this type of charger as Perez99 recommended as well.

 

[Midpack]

This is what I followed.

https://www.tesla.com/sites/default/files/downloads/universalmobileconnector_nema_14-50.pdf

• The installation needs to be done professionally, or equivalent. This is not a DIY YouTube project for 95% of us.
• The wire gauge/quality needs to be adequate.
• The plug needs to be adequate - not a cheapo 240V receptacle like your appliances are plugged into. Your EV charge receptacle will presumably be plugged/unplugged more often than an appliance - and if you're going to do an install, you might as well go for a higher amperage. I have a 50A circuit and plan to charge at 32A - more than adequate to easily charge from 20-80% overnight. I could charge from 0-100% overnight with 32A, but I would rarely if ever charge to 100% and don't plan to run the battery down to nothing. I would not recommend trying to drive charging at the limit of the circuit, e.g. install a 40A circuit to charge at 40A.
• What the OP describes suggests he/she could get by with a lower amperage circuit if already available. Still need to do better than a cheapo appliance grade receptacle.

 

[RetMD21]

Lots of good tips. I didn’t realize that NEMA 14-50 varied in quality. Can you just leave the EVSE plugged in when you aren’t using it? I heard that some of the problems are due to wear from plugging and unplugging. I will have a Model Y long range as of Friday.

The Tesla wall connector would make sense for me since I wouldn’t need an adapter.

I like the idea of solar panels and will be looking into it. I see that the Emporia website talks about integration with solar for solar only recharging. Their system might not work well with a Tesla.

 

[REWahoo]

Lots of good tips. I didn’t realize that NEMA 14-50 varied in quality. Can you just leave the EVSE plugged in when you aren’t using it?

Yes, there is rarely a need to unplug it.

 

[Midpack]

Lots of good tips. I didn’t realize that NEMA 14-50 varied in quality. Can you just leave the EVSE plugged in when you aren’t using it? I heard that some of the problems are due to wear from plugging and unplugging. I will have a Model Y long range as of Friday.

The Tesla wall connector would make sense for me since I wouldn’t need an adapter.

I like the idea of solar panels and will be looking into it. I see that the Emporia website talks about integration with solar for solar only recharging. Their system might not work well with a Tesla.

Yes, there is rarely a need to unplug it.

I plan to use my Tesla mobile connector when I travel, but that won’t be often, so we won’t be in/plugging often. You may unplug more or less depending. As you probably know, charging at home is FAR less expensive than on the road chargers.

 

[Ronstar]

Thanks everyone for posting your charging details.

Originally I planned to tap into our kitchen cooktop circuit for the EV charger. Our cooktop junction box in a lower cabinet is on the other side of the garage wall. 40 amp circuit, never gets used from 7 pm to 6 am. I could install a box for the EV in the garage and run 6" of wire and tie into the cooktop wiring in its existing junction box. I could use the cooktop during the day, charge at night.

Or maybe it would be better to run a separate line for an EV - about 50-60' from charger to main electrical panel.

Anyone share their EV charger circuit with anything else?

 

[audreyh1]

No sharing, our charger circuit goes directly to the breaker panel.

 

[Alan]

No sharing, our charger circuit goes directly to the breaker panel.

Same here.

 

[REWahoo]

No sharing, our charger circuit goes directly to the breaker panel.

And here.

 

[aja8888]

No sharing here either. I have 50 amp breaker dedicated in the panel, #6 copper wire for the run (in 1 1/4" steel conduit) and a Hubbell 14-50 wall connector in the garage.

[/ATTACH]

 

[OldShooter]

... Originally I planned to tap into our kitchen cooktop circuit for the EV charger. Our cooktop junction box in a lower cabinet is on the other side of the garage wall. 40 amp circuit, never gets used from 7 pm to 6 am. I could install a box for the EV in the garage and run 6" of wire and tie into the cooktop wiring in its existing junction box. I could use the cooktop during the day, charge at night. ...

I'm not sure the code allows this. Before you get too committed, I suggest that you call your local electrical inspector and check.

 

[Ronstar]

Thanks everyone. Rather than checking to see if a shared circuit is even allowed under code, maybe I better do a separate circuit. That would be better for resale even if a shared circuit is ok per code. New circuit would be around 100' in length to get from the breaker panel across the whole house to a point even with the back of a car in the garage

Based on what aja8888 has, the new circuit would cost me about $646 in material ($500 for a 125' roll of #6/3 with ground romex, $56 for a 50 amp breaker, and $90 for the receptacle).

 

[ncbill]

Thanks everyone. Rather than checking to see if a shared circuit is even allowed under code, maybe I better do a separate circuit. That would be better for resale even if a shared circuit is ok per code. New circuit would be around 100' in length to get from the breaker panel across the whole house to a point even with the back of a car in the garage

Based on what aja8888 has, the new circuit would cost me about $646 in material ($500 for a 125' roll of #6/3 with ground romex, $56 for a 50 amp breaker, and $90 for the receptacle).

A "smart plug" should cover that, since the appliance that requires a dedicated circuit is given priority over the EV charger, e.g.:

NeoCharge Smart Splitter 240V

 

[Midpack]

Thanks everyone. Rather than checking to see if a shared circuit is even allowed under code, maybe I better do a separate circuit. That would be better for resale even if a shared circuit is ok per code. New circuit would be around 100' in length to get from the breaker panel across the whole house to a point even with the back of a car in the garage

Based on what aja8888 has, the new circuit would cost me about $646 in material ($500 for a 125' roll of #6/3 with ground romex, $56 for a 50 amp breaker, and $90 for the receptacle).

Sounds like a good plan based on what I know.

 

[SnowballCamper]

Our charging circuit is 50 amp. It was originally for a kiln for DWs pottery. Tennis elbow ended the pottery hobby, and the circuit runs the EV charger and the hot tub. Hasn't tripped yet...

 

[aja8888]

Thanks everyone. Rather than checking to see if a shared circuit is even allowed under code, maybe I better do a separate circuit. That would be better for resale even if a shared circuit is ok per code. New circuit would be around 100' in length to get from the breaker panel across the whole house to a point even with the back of a car in the garage

Based on what aja8888 has, the new circuit would cost me about $646 in material ($500 for a 125' roll of #6/3 with ground romex, $56 for a 50 amp breaker, and $90 for the receptacle).

My 50 amp breaker is a GFIC so you might want to factor that in. Also, have the voltage drop calculated for the 100 foot run of #6 copper to see if a heavier gauge is required for the amperage you want to charge at. I can charge at 40 - 48 amps the way I am configured (30 foot run of cable). But I limit it to 32 amps to keep things cool. I think REWhoo is charging at 40 amps and I have too at times.

 

[REWahoo]

I can charge at 40 - 48 amps the way I am configured (30 foot run of cable). But I limit it to 32 amps to keep things cool. I think REWhoo is charging at 40 amps and I have too at times.

I have a 50 amp non-GFIC breaker and an extremely short run, less than a foot. I can charge at 40 amps but rarely do so, also choosing to set it for 32 amps as that generates almost no heat and is plenty fast for my needs.

 

[joesxm3]

Thanks everyone. Rather than checking to see if a shared circuit is even allowed under code, maybe I better do a separate circuit. That would be better for resale even if a shared circuit is ok per code. New circuit would be around 100' in length to get from the breaker panel across the whole house to a point even with the back of a car in the garage

Based on what aja8888 has, the new circuit would cost me about $646 in material ($500 for a 125' roll of #6/3 with ground romex, $56 for a 50 amp breaker, and $90 for the receptacle).

I think romex is not right. I had a 50 or 60 foot run and it used THHN (might have the letters wrong) inside a metal conduit.