48A vs. 40A for home charging??

[txtravwill]

Wire for as high as possible the drop whatever ya want. We are wired from breaker with wire that supports 100amps even, but have 50 amp breakers, and dropped a NEMA 14-50 outlet for now on two chargers. Wiring is the one thing hard to replace in future.

I have a Juicebox 40 plugged in for now. Even charge at 30 amps sometimes to keep everything cool. Plenty fine as usually charge 40-70% or so most days overnight. Or I lower mine at time and charge during day when excess solar can cover most of it to lower bills).

Kinda dropped wire also to support future V2H reverse charging when releases.

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[BigSkies]

I had a 14-50 installed in my garage when I was having other electrical work done. It was when I knew an EV was in my future, but didn't know which brand/model I would buy. I was considering everything from a Leaf to a Tesla to something else at the time.

I now have 2 EV's (Rivian + Tesla) running off that single 14-50 outlet using a Grizzl-e Duo.

There hasn't been a single night where the 40 amps hasn't been sufficient to fully charge both cars.

I like the 14-50 simply for the flexibility. I know the wiring in my garage will be there longer than I have both of my current EV's. While I have no idea what charging standard will be around 10 years from now (maybe NACS version 7 which is not backwards compatible?), everything can plug into a 14-50 outlet.

 

[moosetags]

Bring a Tim Taylor Tool Man type, I did both. I now have the Rivian Wall Charger hard wired in on a 60 amp breaker. I also have a 14-50 outlet on a 50 amp breaker. Both are installed inside the garage on the post between two of the garage doors. This way, I can access the charger from both inside the garage and out on the driveway.

Brian

 

[Feetdry]

I just attended an open house at the Seattle Gear store yesterday and talked over my Rivian charger installation. I hard wired for this charger with #4 copper Romex and a 60 amp breaker. It gives me the opportunity to set it at 48 amps and charge my R1T at 22 mph. The Rivian employees tell me that is good for a home charger on level 2.

2 bays over in my garage, I have a Mean Green Rival zero turn that charges with a plug-in charger at 48 amps and 54 volts at the same time. It doesn't come with the ability to adjust the electrical input. It just charges at that rate.

 

[rdevillers]

I would hardwire if you plan on keeping the car for awhile. It is safer and easier than having to always double check that the plug is inserted.
We have had 2 Teslas since 2015 with 2 Tesla 40amp wall chargers. Day-to-day I charge the cars at 30amps unless I am in a hurry. Charging at 30amps keeps everything cooler and it should be easier on the car and the chargers.

 

[Travis_F]

I am also getting a charger installed for my R1s and will go with hardwired 48A from Emporia (highest rated charger by State of Charge youtube channel), not just for the higher charging speed in case I ever need it but mostly because I want hardwired and not a plug. A plug introduces another contact point in the circuit that I don't want. Like others said above hardwiring is safer, I hear lots of stories for (low quality) NEMA 14-50 plugs melting over time because they are not built for 12-14 hours of max current flowing through them everyday for years.

 

[ThisIsMyHandle]

I have a full 50 AMP (48 usable on RT!) and wouldn't go lower. Our batteries are huge My RT1 charges at 26-27, but my EV6 has a much smaller battery and chargers 33-35 MPH
Check out the different rate here. https://evadept.com/calc/

(I went ChargePoint flex and herd wired to avoid the 20% drop.

 

[HokieBird7980]

We moved a few months ago from a newly built home that had plenty of space in the breaker box so they put a 60AMP breaker in the panel and i consistently got 21 miles per hour charge. New (20yr old house) had no room to add new breakers, so electrician doubled up some others so he could put in a 50AMP breaker. i told him i wanted 60AMP and he would not do it per code in Charlotte saying 50AMP is all that was allowed. I now get 18 miles per hour charge. No big deal when charging overnight and never had a situation where i needed a quick charge. If i ever did, there's plenty of EA or even a RAN charger within 10-30 miles from me where i'd run to in order to charge quicker. And right now the RAN is Free!

 

[ElGuapo]

Hardwire 60A (or higher) to get 48A for Rivian. This is the way.

Rivian’s are just so slow/less efficient to charge (massive battery, whatever - - someone here will correct my wording - I know, I know, it takes more energy to
move a 7,000lb truck, etc). You want every bit of energy you can have. Best you’ll get is 24-25 miles of range per hour at 48A going in.

 

[BCondrey]

I do the missing 3rd option - 30-40 amp charging on a 60 amp circuit. My EVSE can charge at 48A if I need to, but rarely do I need to. Since I plan on keeping the R1S past the warranty, I charge at a lower rate to *theoretically* prolong the battery life. Based on my use patterns, I don't need to top off the battery in 4 hours, I'm fine with 6 or 7. No time of day cost reduction programs, my utility is still in the 1960s mentality.

I charge at 32A on a 48A charger for this very reason, perception of battery health. I have plenty of time to charge at home, no tiered pricing. On the road at rental houses or friends houses I just leave it plugged in all the time to a 120V outlet.

 

[electruck]

Hardwired is the way to go. If you don't have to upgrade your panel (or service), prefer a 60A circuit (48A charging) otherwise a 50A (40A charging) is perfectly adequate. You can always choose to charge slower if you like but you can never charge faster than the circuit can supply should your needs ever change.

I have a 60A circuit and was charging at 48A until the summer heat kicked in. Then the Rivian started having charging errors followed by a software update that throttles charging down to 32A, iirc. I lowered the charge rate on the truck down to 40A which seems to mostly avoid getting throttled down to 32A. Moral of the story is: even if you're equipped for 48A charging, in practice the R1 might only achieve 32-40A dependant on ambient summer temps where you live.

 

[Robotpedlr]

I charge at 40 amps and have never had a problem. I pulled wire for 60amps, installed a 40 amp breaker and a Hubble 14-50. If the promissory note for a V2H charging box ever happens, I can yank the 14-50 plug put in a bigger breaker and hard wire the yet unseen magic box to the 60amp feed.

Not sure if this was a typo - but you can't charge at 40amps with a 40amp breaker. The max you can charge is at 80% of the Breaker rating.

 

[Bob R1T]

I'm debating on 2 different wiring scenarios for installing our Rivian (or possibly aftermarket) wall charger. We are going to be charging an R1S with the 135 kWh Large battery pack. I'd specifically like to hear from anyone currently using 40A to charge their R1 at home. Do you wish you had gone 48A instead? Have you ever run into any hairy situations where you haven't had enough amperage when charging overnight for 75/80% SOC for daily use or 100% SOC for a road trip?

We've had both. A 50A nema 14-50 (Hubble) charging Tesla Y and R1T was OK. It took some coordination occasionally, but very workable. Built a new garage closer to the house, and had to install new 200A service. So naturally, I installed 60A Tesla wall charger, and 60A (Tesla brand) wall charger with plug for the R1T. Wow ! Now both can be charged overnight 0 to 100% (not that I do). Yes, We are lucky to be able to afford the EV's and the charging infrastructure. But driving for 3 cents per mile for fuel, rather than 24 cents per mile for gas, will pay off eventually.

 

[Grabs10]

Install 48 amp hardwire brand of your choice. I DIY installed 2 tesla gen 3 chargers. One for the model 3 with NACS plug and 1 for the Rivian with the J1772 plug. Both wired in with #4 copper and each on its own 60 amp breaker. The load sharing feature of the tesla chargers and the ability not to have adapter to charge NACS and J1772 were the big selling feature as well as the cost.

For me with Idaho Power pursuing those with their own on-site generation and penalizing them it is getting the most of a charger and sending all the power to vehicle will take on is important from a cost viewpoint. Plus having a charger on each side of the garage that can charge at 48 amps is pretty nice.

After having a plug-in 40 amp charger previously when having one EV in the household and taking temps of the outlet while on a lengthy charge session in the heat of summer had me a bit scared enough to hardwire chargers.

 

[Feetdry]

We are lucky in WA to pay $7.50 per month when we supply most of our own power. This Rivian on 60 drawing 48 amps and my Mean Green Rival, zero turn, also drawing 48 amps on a 60 plus room for another EV for the 50 in the new garage. Can't wait to see them all charging at the same time and having to pay the housekeeping electrical fee of $7.50.

So far this new R1T has cost me $10.69 at an EVgo just to try out charging away from home.

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