How many amps should I set R1S for household 110v outlet?

[Thebandit]

Regular household outlet is most likely on a 15 amp breaker.

Code states that continuous loads, such as an ev charger, must be run at maximum of 80% of the circuits max capacity.

That puts you at 12 amps max.

However, if there are other loads on the circuit, you might trip the breaker at 12 amps. So you may want to consider dropping it to 10 or 8 if you need to use other outlets on the same circuit.

If the circuit is a 20 amp circuit, you can safely max out the 12 amps with little worry, unless you're running other significant loads like a heater or toaster on the same circuit.

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[NY_Rob]

After charging for several hours, go touch and feel around the 110V outlet. It may be just slightly above ambient temp but it shouldn't be much warmer than that. 12 amps sustained is a fairly decent load and if it's an older home it's possible the copper wire connections to the outlet screws have slightly loosened over time creating additional resistance manifesting as heat. If it's an outlet that's used frequently, it's also possible that it can be worn down from lots of plugging and unplugging, that will also cause additional heat. Lastly, after charging for several hours, go touch the breaker for that circuit, it should not be above ambient temp.

TLDR: if it's an older house, go feel the outlet and breaker for elevated temps after charging for several hours.

 

[VandalSibs]

It'll actually still allow/advertise 32A of draw on 120V if the 14-50 pigtail is used, with a 3rd party adapter to make it work on a different outlet type. They don't explicitly mention which pigtail is being used the way I read it.

Well yeah, that's because it's being tricked with that extra adapter. That's not the portable charger's fault.

The OP mentioned using a 110/120v outlet in the first post. And while there are a few 120v outlets that pull more than 15 or 20 amps, they are not common in houses.

 

[Greg Chick]

Regardless, if you plug into a circut to EV charge, it is a good idea to watch the charging to see that is is ongoing. Ongoing meaning the breaaker has not tripped. By watching the charging on the dashboard, you will see that the breaker has not tripped and do not need to look in the breaker box of the building.
Like another person posted, the circut you plug into needs to be only powering the EV power cord and not another light or outlet. If the same circut powers the garage door opener, and while charging the EV and you use the door opener, whamo circut will trip. Using the same outlet could be good however by unplugging the door opener to use the charger cord in place. Many garage door openers are on a 20 amp dedicated circut. The age of the building matters in how it is wired. The newer the better.
Is there an elect clothes dryer close by?

 

[VandalSibs]

Oh!! It never occurred to me that the Rivian *charger* itself has a manual! Having had an EV before, I simply pulled out the cable and the adapter I needed. Many thanks for your clarification!

(and yes about upping the charge at a NEMA 14-50: We had one at our previous house)

I had to go check online in the R1 manuals to see if that chart was there myself, as I also couldn't remember. Then I found it in the manual for the charger... which I also didn't remember that chart even existing until Zoidz posted it!

 

[BigSkies]

Everyone is giving good advice here, and I don't have anything to add to it.

I figured I'd pass along basic electrical terminology for future knowledge. Start with the basic formula:

Volts* Amps = Watts.

So a 120V outlet on a 15 amp breaker can put out a max of 1,800W (or 1.8kW). The 80% rule mentioned above for sustained loads works out to 120V * 12A = 1.44kW. There will also be some energy loss between the wall and the battery, so you'll see a little less energy delivered in practice.

The same math works for Level 2 charging; you're just using 240V circuits instead of 120V. A common setup is an EV charger on a 50 amp circuit. So 240V * 50A*80% = 9.6kW.

A dryer circuit or RV park plug would commonly be on a 30A fuse (you can check the breaker box), so you'd want to set the charger at no more than 24 amps, giving you 5.7kW.

 

[NY_Rob]

...The age of the building matters in how it is wired. The newer the better.

Yeah this!

Our house was built in 1964, when I had solar panels installed in 2019 I needed to upgrade to a 200amp service. I asked the electrician to check the gauge of every existing wire running in to the old panel as almost all of them were from 1964 and the printing was completely gone from the sheathing. The original homeowner had a mix of 15 and 20 amp breaker on what looked to be the same gauge wires inside the old panel, so I needed to determine the actual diameter of the wires to size the breakers appropriately once and for all. After a half hour or so, the Electrician came back and said he never saw anything like it before (he had been in the trade for 20+ years).. the actual copper diameter was between 14 and 12AWG diameter! Of course in this case he said we need to go with 15 amp breakers on all the old circuits. In all, IIRC we probably removed about six 20 amp breakers that had been installed by the original homeowner on wires that were really not sized to handle 20 amp loads.

 

[Greg Chick]

Yeah this!

Our house was built in 1964, when I had solar panels installed in 2019 I needed to upgrade to a 200amp service. I asked the electrician to check the gauge of every existing wire running in to the old panel as almost all of them were from 1964 and the printing was completely gone from the sheathing. The original homeowner had a mix of 15 and 20 amp breaker on what looked to be the same gauge wires inside the old panel, so I needed to determine the actual diameter of the wires to size the breakers appropriately once and for all. After a half hour or so, the Electrician came back and said he never saw anything like it before (he had been in the trade for 20+ years).. the actual copper diameter was between 14 and 12AWG diameter! Of course in this case he said we need to go with 15 amp breakers on all the old circuits. In all, IIRC we probably removed about six 20 amp breakers that had been installed by the original homeowner on wires that were really not sized to handle 20 amp loads.

If you have that much view on the the system can you know the circut load of the outlet you need to use to EV charge? If so, can you isolate and use only the EV load? Next to a clothers dryer 220 VAC that is your only hope.

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