Portable charging cable on 20amp circuit

[dekeen]

So I have contacted Rivian support twice and am getting conflicting information. I have a 240v, 20amp circuit. It’s a long story and I cannot rewire the circuit for greater amperage. My question pertains to the portable charging cable with the L2 14-50 plug. If I use this on the 20amp circuit will the Rivian trip the breaker or just pull the available amps and charge slower?

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[zipzag]

Can you not set the level in the truck to 16 amps? (80% of 20 amps)

 

[ajdelange]

You will have to get an adapter between whatever receptacle you have and a 14-50R receptacle into which you can plug the 14-50P pigtail from the mobile "charger" unit. Wire the two hots an earth/ground. Do not wire the neutral.

When using this adapter you MUST reduce the charging rate in the car to 16A. The 14-50 pigtail programs the "charger" to tell the truck it can ask for 32 A and if you don't set the lower rate in the truck it will do exactly that i.e. ask for 32 A which will pop the breaker.

 

[Dark-Fx]

The portable charger can't be configured to announce less than 32A, you will have to set the charge rate in the vehicle to 16A.

 

[dekeen]

Can you not set the level in the truck to 16 amps? (80% of 20 amps)

Thanks. Not sure. I don’t have the truck yet, but have seen this discussed. That would definitely solve the issue, but still curious as to what would happen if I couldn’t tell the truck to only draw 16amps.

 

[CommodoreAmiga]

You need to limit your charging to 16A via the infotainment system (which can be done).

 

[CommodoreAmiga]

Thanks. Not sure. I don’t have the truck yet, but have seen this discussed. That would definitely solve the issue, but still curious as to what would happen if I couldn’t tell the truck to only draw 16amps.

If you didn't limit charging to 16A via the infotainment system, you'd hopefully trip the breaker... If that failed, you could cause a fire by drawing more current than the circuit could handle, which heats things up, can melt insulation, cause shorts, etc.

 

[ajdelange]

The portable charger can't be configured to announce less than 32A, you will have to set the charge rate in the vehicle to 16A.

Well yes it can. If, for example, if you plug in the 120V pigtail it will program it to ask for 12 A. Presumably if the pigtail has the right programming resistor in it it will program for whatever is compatible with the pigtail plug.

 

[ajdelange]

...but still curious as to what would happen if I couldn’t tell the truck to only draw 16amps.

The 14-50 pigtail programs the "charger" to tell the truck it can ask for 32 A and if you don't set the lower rate in the truck it will do exactly that i.e. ask for 32 A which will pop the breaker.

 

[Dark-Fx]

Thanks. Not sure. I don’t have the truck yet, but have seen this discussed. That would definitely solve the issue, but still curious as to what would happen if I couldn’t tell the truck to only draw 16amps.

The truck would draw 32A and the breaker would trip. Not immediately though, likely somewhere between 10 and 60 seconds.

 

[swazi]

To the OP, I have a spare tesla mobile connector and the correct adapter for 240v 20amp. Coupled with a teslatap mini I was able to charge the Rivian without problems. Only wonky thing was that the rivian wanted to pull 18amps, so I reduced it to 16.

 

[Brewbud]

I am using the portable charger right now. You can easily program the R1T to draw less current for your situation. I have mine plugged into a NEMA 6-50 outlet (240 50A for my welder) using an adapter. I have turned the amp draw in the R1T to 22A. Even though the adapter is rated for more, I don't need higher amps right now and I feel better about it.

My Rivian charger is waiting to be installed.

 

[pc500]

Go to amazon.

"240v 20amp evse". Spend the $100 and move on.

Don't trust that you'll set the charge voltage right if you'll be using it every night.

It should charge at 16 amp.

 

[Brewbud]

Go to amazon.

"240v 20amp evse". Spend the $100 and move on.

Don't trust that you'll set the charge voltage right if you'll be using it every night.

It should charge at 16 amp.

You don't have to set it every night. Set it once and it stays that way until you change it. It knows you are at home.

 

[pc500]

You don't have to set it every night. Set it once and it stays that way until you change it. It knows you are at home.

As long as it remembers safely at the house, I guess it's ok. It just seems like an accident/fire waiting to happen if it "forgets". If you're willing to give up your portable charger to your garage (or pack it up every trip), then you have an option.

I have always reserved manually downrated charging though for one-off situations at a random outlet.

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