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48A vs. 40A for home charging??

What amperage do you recommend for home charging an R1S?


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Baymax

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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?
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Stevetom84

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I have a 40A juice box with a NEMA 14-50 plug that I bought a couple years ago through GA Power when I got a VW ID.4 (we already had a 14-50 outlet in the garage). I’ve had no issues getting sufficient charge at 40A on my R1T. My daily commute is relatively short and and I have the R1T set for 70% charge. If you already have a NEMA 14-50 outlet, I would probably just go with a 40A charger, unless you consistently travel long distances that require you to charge to higher levels. If you are starting fresh without any infrastructure, I would go with the 48A. The installation cost difference between a 50A circuit and a 60A circuit would be fairly minimal (unless your feed is long). Obviously one good thing with a NEMA 14-50 unit is that it can be easily changed out in the event it dies. Changing out a hardwired unit isn’t difficult, but some may not be comfortable taking it on.
 

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To charge from 30% to 80% would take approximately 6.5 hours on 48 amps. The same would take an extra 1 hr and 50m on 40 amp. (Just under 8 hr). Both are acceptable charging speeds. The only difference would be if you need to charge frequently and you need quickest possible charging. If you can go with 48 amps do that but if it's not reasonable 40 amps is perfectly acceptable and will still charge that 50% overnight without issue.
 

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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.
 
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Baymax

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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.
That's super helpful and might be the route I end up going. You're using a non-Rivian EVSE? I'm assuming the Rivian wall charger lets me adjust the charging rate into the battery? i.e. keep it at 30-40 amps for 70/80% daily SOC, & bump it up to 48 amps to get to 100% SOC prior to a road trip?

Does the Rivian mobile app synced with the Rivian wall charger allow you to adjust the amperage into the vehicle?
 

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I'd specifically like to hear from anyone currently using 40A to charge their R1 at home.
I've got a 48A charger, wired to 48A, but have it set to 40A because that's what my extension is rated for. More than enough most times, but I will occasionally plug right into the charger in situations where I need the extra for whatever reason. IMO it's always better to have the capability.
 

Donald Stanfield

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I set mine to 48 with the 60A breaker and it's good, but I would probably be more than fine with the 40 as well. So the poll should have an either way it doesn't make a ton of difference option.
 

centexR1S

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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?
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.
 

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I would suggest if installing from scratch go with a 60 or higher amp circuit if you have the room just for future options.

If you already have a 50 amp circuit use that and charge at 40 amps. I get between 18 and 20 all purpose miles charging at 40 amps, that is around 100 miles in 5 hours.
 

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That's super helpful and might be the route I end up going. You're using a non-Rivian EVSE? I'm assuming the Rivian wall charger lets me adjust the charging rate into the battery? i.e. keep it at 30-40 amps for 70/80% daily SOC, & bump it up to 48 amps to get to 100% SOC prior to a road trip?

Does the Rivian mobile app synced with the Rivian wall charger allow you to adjust the amperage into the vehicle?
I use OpenEVSE so I can't speak to the Rivian brand EVSE.

You can set charge rate in the vehicle, or with OpenEVSE you ca set the charge rate via WIFI or the front panel.

Note that OpenEVSE is not UL approved so that can be a problem, I've read that some electricians look for the UL sticker and won't install it. The individual components are UL, but the OpenEVSE assembly is not.
 
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60 amp if your battery capacity is triple digits kWh and 50 amp if it’s double digits kWh capacity.

anything else is like watching paint dry.
 

iansriv

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After researching this board, I just ordered the Emporia and plan to plug it in instead of hardwiring. It's a 60amp circuit. This set up allows me to switch chargers IF I need to in the future.
 

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Go with hard wired if you can. Put the highest amp evse your house and budget can support; anywhere from 30-48A will get you charged overnight without any concerns.
If you frequently need to get juice for last minute trips or after a commute and don't have dcfc nearby then 48A is really nice to have.
 

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If you can, it's better (safer) to hardwire a charger. If that's not possible in your case, then make sure you're using a good quality 240V outlet that's rated to handle the load of an EV charger. Many regular dryer outlets aren't designed to handle that kind of load. Just my $0.02.

https://insideevs.com/features/625675/how-to-install-ev-charging/
 

WorldComposting

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A lot of the people who know charging really recommend hardwiring so I would recommend that. If you ever plan on having two EVs I would highly recommend going 48.

The electrician who came out recommended hardwiring when I asked for their opinion and I think a plug was more expensive as they would be adding an outlet.
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