Slow Charging/Warm Plug on Rivian Home Charger

[LNJ]

I’m having same issue. Two years ago I learned that my Rivian sucks at L2 garage charging in any heat. In cooler months there are no issues. So going into this summer I was not surprised when it would derate from 11 to 7.2ish every charge after about 30 minutes. But recently it’s been cooler, garage temps in the 70s and it’s still derating every time. I even have a garage fan pointed right at the port to circulate air around. Just doesn’t want to maintain charge at 48a. I don’t have a temp gun but the handle has never been that hot to the touch. Using Tesla charger with a2z stellar adapter. Charger will charge non Rivians (well, I have only tried teslas) outside of garage in direct sunlight in summer without derating so it’s not the charger. Possibly the adapters intruding additional heat. But would put money on it being a thermal issue with the truck. 23 R1T. It’s annoying but I’ve leaned to plan around it, Rivian tax

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[ndmiller]

Been L2 charging EV's off my charge point flex for almost 4 years, never outside of the 8.8-9.2KW on any vehicle. Something up with your wiring causing extra resistance?

I'm in ATL and they all charge outside and we have some heat.

 

[MMC3]

Been L2 charging EV's off my charge point flex for almost 4 years, never outside of the 8.8-9.2KW on any vehicle. Something up with your wiring causing extra resistance?

I'm in ATL and they all charge outside and we have some heat.

Not wiring. It worked fine for 2 years Something in the Rivian Gen1 and/or Rivian charger changed over the past year. I sent my R1S for service and they told me everything checked ok. However, at the Rivian Service Center, the throttling occurred after 2 hrs of charge and they didn't even notice. I sent them the charge curve. The R1T Gen1 loaner also slow charged at my home charger. I charged my R1S at a commercial 40A location after I picked it up from service and saw no throttling for 3 hrs, granted it was at 40A. I set the max charge to 40A at my home charger and it throttled after about an hour. I also tested my Rivian Home Charger with a Cybertruck and it did fine. I think it is both the Rivians AND the Rivian home charger. It is definitely heat related. I am in Texas.

 

[1stPlace]

I’m having same issue. Two years ago I learned that my Rivian sucks at L2 garage charging in any heat. In cooler months there are no issues. So going into this summer I was not surprised when it would derate from 11 to 7.2ish every charge after about 30 minutes. But recently it’s been cooler, garage temps in the 70s and it’s still derating every time. I even have a garage fan pointed right at the port to circulate air around. Just doesn’t want to maintain charge at 48a. I don’t have a temp gun but the handle has never been that hot to the touch. Using Tesla charger with a2z stellar adapter. Charger will charge non Rivians (well, I have only tried teslas) outside of garage in direct sunlight in summer without derating so it’s not the charger. Possibly the adapters intruding additional heat. But would put money on it being a thermal issue with the truck. 23 R1T. It’s annoying but I’ve leaned to plan around it, Rivian tax

This sounds like the issue I had, which turned out to be an issue with the temp sensor and wiring harness. I replaced the Rivian wall charger first under warranty but still had same issue. I sent multiple pictures to customer support to document. It took some persistence, but eventually the service center was willing to fix it under warranty. But it was super expensive, several thousand dollars, so you may need to exhaust all the other possible reasons with the service center and support first. Keep in mind, its a lot easier to document, or for the service center to test, when the weather is actually warm, so you might have missed some opportunity to resolve this this year, but remember to try again in the Spring. It is NOT "within spec" or a thermal issue.

 

[Semibruce]

Update... I quickly got a call from Rivian Service after uploading the requested photos. They're going to send me a new charger. They also noted that since I have a single wire (instead 2 x 110v),that I should change my dip switch settings from 48A to 40A.

 

[Trex_RT [SCAMMER]]

I’m having same issue right now,

 

[Semibruce]

Confirming... Just received my replacement this morning. FYI, they request that you send the old one back to them.

 

[GriffJP]

My charging was working perfectly. I bought my initial charger with my launch edition R1T which I received in May 2022. I upgraded to a generation2 Tri-motor Ascend in November 2024. Same wall charger. I did the Halloween update that came out most recently, and my charging has been fickle ever since. I have reset the charger. I have deleted the charger and reinstalled it. I have reset the vehicle software. And restarted the vehicle software. My charging has been flawless before this Halloween update. Has anyone else had a similar experience with the charging failing after the most recent Halloween update? The warning I've been getting is either the charging has been slowed due to a warm plug or a red light on the charger button when you open the charger door indicating a vehicle error. As I've stated, I have reset the charger itself at least twice. I also finally restarted and reset the vehicle. It appears to be charging well right now and appeared to charge well earlier today but intermittently it will stop charging due to a 'vehicle error' and ask me to unplug and plug in again or it will slow charging from 11.3 kW to 3.2 kW due to a warm plug. I've never had this issue before in the three years of ownership of both a Gen 1 and Gen 2 R1T until this most recent Halloween update.

 

[RoBoRaT R1S]

My charging was working perfectly. I bought my initial charger with my launch edition R1T which I received in May 2022. I upgraded to a generation2 Tri-motor Ascend in November 2024. Same wall charger. I did the Halloween update that came out most recently, and my charging has been fickle ever since. I have reset the charger. I have deleted the charger and reinstalled it. I have reset the vehicle software. And restarted the vehicle software. My charging has been flawless before this Halloween update. Has anyone else had a similar experience with the charging failing after the most recent Halloween update? The warning I've been getting is either the charging has been slowed due to a warm plug or a red light on the charger button when you open the charger door indicating a vehicle error. As I've stated, I have reset the charger itself at least twice. I also finally restarted and reset the vehicle. It appears to be charging well right now and appeared to charge well earlier today but intermittently it will stop charging due to a 'vehicle error' and ask me to unplug and plug in again or it will slow charging from 11.3 kW to 3.2 kW due to a warm plug. I've never had this issue before in the three years of ownership of both a Gen 1 and Gen 2 R1T until this most recent Halloween update.

Some similarities here.

Never had any “charger error” since delivery August 2023 built R1S until L2 charging at home, first time to charge after 2025

Halloween update.

The error comes with using NACS to J1772 adapter with Tesla Gen2 Wall Connector or Mobile Connector. Both these Tesla chargers work with our Tesla car.

There is no charger error using the Rivian Mobile Charger.

 

[Semibruce]

I've had no issues since the update and can't speak to Tesla Chargers. I did, though, want to share an update on my situation....

Long story short, I now realize that my licensed electrician used the wrong cable type to support a sustained 48A charge. My setup uses 6/2 Romex NM-B cable, which is only rated for 55A. Because EV charging is considered a continuous load, that cable can safely support 40A max, not 48A.

I had my DIP switch set to 48A, which likely caused the “warm plug” and derating issues I’ve been seeing. Maybe it even stressed the charger over time—but thankfully Rivian replaced it under warranty.

I installed the replacement charger yesterday, and it worked perfectly, but only charged at 8.8 kW (down from my previous 11+ kW). That’s the new normal for me unless I upgrade the wiring.

Per ChatGPT (and confirmed by NEC guidance), here’s the rationale:

NM-B cable is rated for 60 °C ampacity, which limits #6 AWG copper to 55 A. Since EV charging is a continuous load, wiring must be rated for 125% of the draw—meaning a 48 A charger needs conductors rated for 60 A. My 6/2 NM-B cable just doesn’t meet that threshold.​

So, if your Rivian (or any) charger keeps derating or shows “warm plug” messages, check your wiring type. If it’s NM-B Romex, your safest bet is to drop the DIP switch to 40A or upgrade to conduit with #6 THHN wire.

 

[NSRoamer]

Thank you very much for posting this, Bruce. Caught this thread just in time to avoid making the same mistake. Got the ChargePoint Flex - just waiting for a few reasonably warm days to install.

 

[MMC3]

Rivian sent replacement home chargers for both of my locations. All my charging is now working as expected and back to what I originally had for 2 years; full capacity at 48A.

It appears that something had started to fall in the original Rivian Home Chargers.

 

[NSRoamer]

I don’t know if the problem is the ChargePoint or the R1T. Got the 60 amp breaker, #6 THHN cables, but the T charges at 40 amps - adds 25 miles or range per hour according to the truck. The amp draw reading on the THHN is 47 amps. ChargePoint and truck both set to 48 amps - which should add 36 mph according to ChargePoint. I have a service ticket in with CP, but now I’m thinking I probably should have dropped a bit more money and bought the Rivian charge connector.

Or maybe not - looking at the Rivian charger, it “delivers up to 25 miles of range per hour” - although the max current is 48 amps.

The most evil Dominion Power does have a “Super off peak” rate from midnight to 5 AM all year round. The regular off peak rate varies depending on weekday, weekend, holiday and season. Although Rivian has off peak as one of the schedule options, it doesn’t have super off peak. I have the truck scheduled to charge from 12AM to 5AM.

If anyone has a different experience with ChargePoint, I’d like to know about it.

I appreciate all the info on this forum - and some of the snide comments. Probably should have started a new thread since I’m not using a Rivian charger - but all this is making my head spin.

 

[VSG]

Rivian sent replacement home chargers for both of my locations. All my charging is now working as expected and back to what I originally had for 2 years; full capacity at 48A.

It appears that something had started to fall in the original Rivian Home Chargers.

Again, for the umpteenth time, this is probably a problem with your install, not with the charger. Repeated heat/cool cycles (charging under high amps) will stress your electrical connections, and if they are not torqued properly they will loosen with time. If it worked properly for 2 years then started failing, chances are the screws loosened enough to increase the resistance and cause the problem. The solution is to tighten your screws. Period. It still amazes me that Rivian keeps replacing chargers for free when it's almost certainly a problem that could have been avoided if the electrician paid attention.

the T charges at 40 amps - adds 25 miles or range per hour according to the truck. The amp draw reading on the THHN is 47 amps. ChargePoint and truck both set to 48 amps - which should add 36 mph according to ChargePoint

I don't think you understand what you are seeing. A Rivian can charge at a maximum of 48A, which equals 11.5kW, which is about 25 miles of range per hour (although "mph" is a TERRIBLE unit of measure). There is no way a Rivian can L2 charge at "36 mph".

 

[DrBluey]

I had the same issue with the Rivian charger, decreasing charging speed to about 7 kW after about 15 to 20 minutes of charging. I finally switched to a Tesla universal charger and have not had a single problem since. I get 11 to 11.3 kW consistently.The problem is definitely the Rivian charger.

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