Connected Home Charger - Speed Decreasing on 100A Circuit

[Chrome]

The question: is it a bug, or a feature?

Well, I took a look at my 14-50R outlet (Photo attached) and it certainly appears to resemble the lesser-quality version (Searched image LEFT). It does not have the additional clearance around the blades. I haven't removed the cover plate to inspect things further.

Of course I made it abundantly clear to the electricians that I would be charging an EV at 40A continuous, but apparently they cheaped out on the receptacle. 50A breaker was installed as expected, and I can only assume the choice of wiring was appropriate for the current (Have to question that now, too, I guess.)

This work was done in August of 2024, and the throttling did not begin until May of 2025. I'm led to conclude that, in my scenario, either:
A) The software was updated to actually respond to dangerously high temperatures at the outlet. I was just "lucky nothing happened" for the past year, as I regularly charged at 40A.
or
B) The software/Control Unit has always been capable of throttling this way, but the outlet finally became damaged enough (as of May, rather coincidentally) to cause excess/uncontrolled heat and now I'm seeing an automatic response to this.


Hopefully I'm not derailing the thread as it was originally discussing the LCHC in particular. Very similar symptoms, potentially different causes.

 

[Miami_Lucid_Man]

Well, I took a look at my 14-50R outlet (Photo attached) and it certainly appears to resemble the lesser-quality version (Searched image LEFT). It does not have the additional clearance around the blades. I haven't removed the cover plate to inspect things further.

Of course I made it abundantly clear to the electricians that I would be charging an EV at 40A continuous, but apparently they cheaped out on the receptacle. 50A breaker was installed as expected, and I can only assume the choice of wiring was appropriate for the current (Have to question that now, too, I guess.)

This work was done in August of 2024, and the throttling did not begin until May of 2025. I'm led to conclude that, in my scenario, either:
A) The software was updated to actually respond to dangerously high temperatures at the outlet. I was just "lucky nothing happened" for the past year, as I regularly charged at 40A.
or
B) The software/Control Unit has always been capable of throttling this way, but the outlet finally became damaged enough (as of May, rather coincidentally) to cause excess/uncontrolled heat and now I'm seeing an automatic response to this.


Hopefully I'm not derailing the thread as it was originally discussing the LCHC in particular. Very similar symptoms, potentially different causes.

No worries I think it’s worth discussing more than just the Lucid charger bc it’s happening on other chargers. The common thread among all posts seems to be the timing.

 

[DeaneG]

Well, I took a look at my 14-50R outlet (Photo attached) and it certainly appears to resemble the lesser-quality version (Searched image LEFT). It does not have the additional clearance around the blades. I haven't removed the cover plate to inspect things further....Hopefully I'm not derailing the thread as it was originally discussing the LCHC in particular. Very similar symptoms, potentially different causes.

I think it's good that you posted, as we can't automatically assume it's the car software.

My own guess is that ordinary thermal cycling on your oven-rated receptacle has loosened one of the wire connections enough to start causing a problem. There's enough copper around that when the receptacle overheats, the heat travels into the plug and cable, which you can feel.

One of many old threads on the issue: https://lucidowners.com/threads/har...ant-cooper-14-50-receptacle-not-leviton.6537/

 

[skomarla]

I was facing the same issue and flagged it to a mobile service technician who was seeing my car for a different reason. I provided date and time of each charge session when I plugged in, along with charge rate drop. He shared it with engineering and after 2-3 weeks, got back to me - "if it is warm inside the garage, the lucid charging station will drop the charge rate to cool down". He further told me "The best setting during the summer months should be around 56amps to avoid it overheating and throttling down."

I went ahead and changed the dip switch to 56amps and do not face the issue anymore.

well summer months is a bit of a generic term as temperatures do vary based on location. where are you located and how many cycles have you done at 56kw?

i'm not entirely buying that yet. in the northeast, a good summer day may still be cooler than a winter day in florida, arizona etc. honestly, i don't recall 18 dropping to 7 last summer. i would have noticed it at somepoint.

 

[Sandvinsd]

It is the car software cycling the amperage, probably heat related on the plug or the car itself. As for the last several months, ever since one of the updates (don’t remember which) my Lucid Home Charger will cycle between the 80 amps it is hardwired for down to 40 amps periodically. If I lower the amps on the charger to 40 or 45, it doesn’t cycle. I’m charging at night in coastal SD so it is not the garage being warm, although probably a combination of many things that the car senses to cause it to lower the amp pull.

 

[skomarla]

a few more observations from today

I just ran the unplug and replug test and it only worked momentarily.
- started charging at 18kw
- i checked again 13 min later and it was down to 8kwj, ust under 50% of what should be available
- i stopped the charging, unplugged and plugged it back in, and it jumped up to 16 and then 18 within seconds
- after 3 mins, it was back down to 8kw, just under 50% of what should be available

so unplug/replug didn't resolve this.

i then dropped the current limiter down from 80a to 56a and the car only started pulling 5kw. interestingly, thats near the 50% of what the theoretical draw should be if it pulled all 56a. i then dropped the draw to 40a and the car only pulled between 3-4 kw. again under 50% of the available current.

so if the temp was driving the draw, it should keep drawing the 8-9 kw, even if the limiter is set to 40a, but its not.

garage temp was ~85F

 

[SBD1500]

I think this happed after a software update. I hope Lucid is working on a fix. I bet this is more common than what the forums show.

 

[Miami_Lucid_Man]

a few more observations from today

I just ran the unplug and replug test and it only worked momentarily.
- started charging at 18kw
- i checked again 13 min later and it was down to 8kwj, ust under 50% of what should be available
- i stopped the charging, unplugged and plugged it back in, and it jumped up to 16 and then 18 within seconds
- after 3 mins, it was back down to 8kw, just under 50% of what should be available

so unplug/replug didn't resolve this.

i then dropped the current limiter down from 80a to 56a and the car only started pulling 5kw. interestingly, thats near the 50% of what the theoretical draw should be if it pulled all 56a. i then dropped the draw to 40a and the car only pulled between 3-4 kw. again under 50% of the available current.

so if the temp was driving the draw, it should keep drawing the 8-9 kw, even if the limiter is set to 40a, but its not.

garage temp was ~85F

Good intel.

85 is warm but i mean, many parts of the US get that hot routinely in a garage. You'd think it could handle it.

 

[ERdoctor23]

Was it the AC or the car’s fans cooling the battery? I ask because I am wondering if this is a software issue or an ambient temperature issue. @borski and I have had some back and forth on this in another thread.

I’ve had throttling of my Tesla gen 3 wall charger around the time of I believe the 2.7.0 update but it was also getting warmer down here with summer here. That said I never had this issue when I had my Tesla.

Each time I have started charging and forgot to turn off the AC it begins at a slow trickle rate. Again I will stop charging, unplug, turn off the AC and plug back in. Will get up to 77-79 mi/hr.

 

[sbr41]

well summer months is a bit of a generic term as temperatures do vary based on location. where are you located and how many cycles have you done at 56kw?

i'm not entirely buying that yet. in the northeast, a good summer day may still be cooler than a winter day in florida, arizona etc. honestly, i don't recall 18 dropping to 7 last summer. i would have noticed it at somepoint.

I agree, I did not notice it happening last summer, and I also noticed it happening only after SW update (IIRC 2.6.16). So it is likely a heat management update in the SW that is causing it. I have been at 56amp for almost 3 weeks now and all charge sessions had a consistent charge rate of 13kW.
Also, I am in DFW area.

 

[Miami_Lucid_Man]

I agree, I did not notice it happening last summer, and I also noticed it happening only after SW update (IIRC 2.6.16). So it is likely a heat management update in the SW that is causing it. I have been at 56amp for almost 3 weeks now and all charge sessions had a consistent charge rate of 13kW.
Also, I am in DFW area.

Yes I think it was that update. The one right before 2.7.

 

[SBD1500]

Garage is 75 degrees in the Seattle area. I have a fan pointed directly at charging port. I still got slow down after about 30 mins. From 11kw to 5 kw. This is on my 2 week old Touring. But the same behavior on my previous 2 yr old Pure after a software update maybe 6+ months ago. I know I'm not the only one. Hopefully a fix is in the works.

 

[Miami_Lucid_Man]

This is all really good data we’re compiling in this thread on this issue. The Seattle example above seems to strongly point to a software issue from that update just before 2.7.0. But as @DeaneG said, maybe it was intentional for safety reasons? I’d still like to know either way.

 

[DeaneG]

It would be useful to hear Lucid's view on this.

 

[Cabonzhp]

With 2.8.0 introducing charge current limits on the car, it also displays the maximum limit of the EVSE (charger). I’d be curious when you see the charging power drop if that currently selection limit on your screen has dropped from 80A. If it does, that would indicate to me that it’s the charger

 

[borski]

With 2.8.0 introducing charge current limits on the car, it also displays the maximum limit of the EVSE (charger). I’d be curious when you see the charging power drop if that currently selection limit on your screen has dropped from 80A. If it does, that would indicate to me that it’s the charger

It doesn’t.

 

[skomarla]

I realized that when I ran the 56a and 50a “tests” that the car was already in a throttled state. The past few days when I need to charge on separate occasions, I initiated sessions at 40a and 56a separately and kw stayed stable the entire charge cycle which lasted 3 hrs and 1.5 hrs respectively fluctuating by 1-2 max. Ambient temp was still in 80s.

Also I txted with my sales advisor, and he said the issue with charging at 80a is known and a patch should fix it. Thats not an official statement by any means but atleast its possible that it’s a software issue.

 

[Miami_Lucid_Man]

I realized that when I ran the 56a and 50a “tests” that the car was already in a throttled state. The past few days when I need to charge on separate occasions, I initiated sessions at 40a and 56a separately and kw stayed stable the entire charge cycle which lasted 3 hrs and 1.5 hrs respectively fluctuating by 1-2 max. Ambient temp was still in 80s.

Also I txted with my sales advisor, and he said the issue with charging at 80a is known and a patch should fix it. Thats not an official statement by any means but atleast its possible that it’s a software issue.

Interesting. I’ve tried dialing down to 32 amp off of 48 and I still had the same throttling. If what he says is true, hopefully that would also apply to us charging at home at lower amps.

 

[dcr33313]

I’m in South Florida and it’s only cooler than 85 like 1-2 months out of the year. I didn’t have this issue for the entire first year of ownership. There was even an unusually cool night a few weeks ago where the car still lowered the charge rate after a while. The charging cable is very thick so that it can handle the heat of charging at 80A, so I don’t see Lucid throttling their own charging equipment because of that…not to mention that the issue is happening with Tesla and other EVSE as well. I sure hope they release that patch soon; it’s been months and a handful of updates already.

@borski Do you experience this issue with your wife’s Gravity?

Thanks for everyone’s additional insights.

 

[Miami_Lucid_Man]

I’m in South Florida and it’s only cooler than 85 like 1-2 months out of the year. I didn’t have this issue for the entire first year of ownership. There was even an unusually cool night a few weeks ago where the car still lowered the charge rate after a while. The charging cable is very thick so that it can handle the heat of charging at 80A, so I don’t see Lucid throttling their own charging equipment because of that…not to mention that the issue is happening with Tesla and other EVSE as well. I sure hope they release that patch soon; it’s been months and a handful of updates already.

@borski Do you experience this issue with your wife’s Gravity?

Thanks for everyone’s additional insights.

Thanks for the data point.