Home charging plan

[mudito]

Interesting, I thought about a subpanel but didn't think it was worth it for this 1 dedicated circuit. I truly don't see needing a second EVSE in my future. Although you have a good point about future battery sizes. Something for me to think over.

my Rivian charger has about 35-40ft of wiring. I did not install a subpanel for it, just a 60Amp breaker with 4 awg copper wiring on a 1" PVC electrical conduit.
I know I went a bit over-the-top with the wire gauge, but I wanted peace of mind. I also wired my wife's Tesla Wall Charger but limited to 40amp breaker (32amp charging) with 8 awg wire. That was a MUCH easier wiring process, still about 40ft but into another direction

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[BCondrey]

I have a Grizzl-e classic, in use at 40A on a 50A circuit, on a NEMA 14-50. It is a tank. I get about 9KW out of it. It is not simple to hardwire, you will need to get the right size lugs and crimp them to specs. I think there is a post on reddit with instructions.

Rivian wall EVSE can be found on e-bay, new in box, for deep discounts. Thats a hardwire unit.

 

[Bullwinkle]

Now that I have committed to getting a R1T, I am starting the next item on the agenda. Getting and installing a home charger. I'm going to share my plan and those who have gone through this already can let me know if I'm way off base on something.

I've looked around and I will get the Grizzl-E classic 40A charger. I'm thinking a basic unit is all I need as I understand the Truck can do the charge scheduling and whatnot.

I plan to do the installation myself. My main panel is 200A and my rough guesstimate is the charger will be over 50 ft from the panel (thinking of the actual routing of conduit, not a straight line) but definitely less than 100 ft. 50A breaker, 3/4" conduit, #6 solid copper wires, 2 'hots' and 1 ground. My preference is to hardwire it but, if need be, I would get a quality NEMA 6-50 outlet.

I would consider NEMA 14-50 instead of 6-50. I like Autel chargers quite well also.

 

[Luxus]

My preference is to hardwire it. I have no intentions on adding any other electrical circuits in the garage where the Rivian will be parked. I have a second garage with a sub panel where all the various pieces of equipment I have get plugged into. If I had just the one garage then you guys are making some good suggestions.

 

[mkhuffman]

I hear you but if you are familiar with NEC requirements on sizing, and you use common sense, AND you have done electrical wiring before, it isn't dangerous.

I would not recommend attempting this if it is the first electrical wiring you have ever done for the reason you stated: this is one that really could burn your house down.

Dryer sockets are not designed for BEV use, so if anyone does that, you really need to drop the current down well below the rating on the outlet. You need to make sure the wire is sized properly and definitely a dryer outlet is not BEV quality. If the current is low enough, it should be fine.

Instead of the 20% rule, I would keep the current 30% below the breaker rating and it will probably be OK, but I am not basing that on anything but my opinion. I would not follow the 20% rule on a dryer outlet and circuit for a BEV use case.

Edit: fixed brain fart on the current requirements.

 

[BCondrey]

I hear you but if you are familiar with NEC requirements on sizing, and you use common sense, AND you have done electrical wiring before, it isn't dangerous.

I would not recommend attempting this if it is the first electrical wiring you have ever done for the reason you stated: this is one that really could burn your house down.

Dryer sockets are not designed for BEV use, so if anyone does that, you really need to drop the current down well below the rating on the outlet. You need to make sure the wire is sized properly and definitely a dryer outlet is not BEV quality. If the current is low enough, it should be fine.

Instead of the 10% rule, I would keep the current 20% below the breaker rating and it will probably be OK, but I am not basing that on anything but my opinion. I would not follow the 10% rule on a dryer outlet and circuit for a BEV use case.

What 10% rule? The rule is to run at 20% less than capacity for continuous load devices (or something like that).

 

[mkhuffman]

What 10% rule? The rule is to run at 20% less than capacity for continuous load devices (or something like that).

See there! That kind of mistake is the kind that will cause problems. I will fix the previous post. The point I tried (and failed) to make was the standard derating rule is not good enough for a dryer outlet. So 20% is not good enough. Maybe 30% is OK.

 

[beatle]

Yeah, EVSE/constant load requires 20% derating.

I'd install a Tesla UWC where you want it right now. You can daisy chain another one (or two, or five) off the original one on the same circuit. If you're charging more than one EV, they will share the circuit's capacity. Even if you only have one EV, additional EVSEs can give you some freedom when parking if you have more than one place, but you can always install another one later.

A 50A circuit will let you do 40A charging, which even on a max pack, will put about 6.5% into the battery per hour. That's enough to go from 10-80% in under 11 hours.

 

[BCondrey]

See there! That kind of mistake is the kind that will cause problems. I will fix the previous post. The point I tried (and failed) to make was the standard derating rule is not good enough for a dryer outlet. So 20% is not good enough. Maybe 30% is OK.

The question is, how far do you have to de-rate it to make it safe? How do you know? Is it EVER safe with a continuous load at any amperage. A dryer outlet is a poor choice regardless, unless you re-purpose the wiring to provide two hots and a ground. Hardwire it and only derate by 20%.

 

[docwhiz]

Check with your local electrical utility to see if they have any programs for discount rates, and make sure they don't specify a particular make/model of charger. Case in point- here in MN if you want to take advantage of Xcel's EV program you have to use a Chargpoint EVSE. That particular charger can communicate with Xcel's billing software. If you want to bring your own charger, you'd need to either install a separate meter and/or switch to a new billing plan for your whole house. So, before you buy, make sure you don't have get a specific charger to get a discounted rate-if you want to participate in that program.

My utility (Liberty) in California offered a free ChargePoint charger and paid for the installation.
Worth checking out.

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