Home charging fluctuates from 8 kw to 4 kw

[Bodyhauler]

I have a Nema 14-50 outlet in my garage and have my Mobile Charging Unit plugged in for charging. Recently I've noticed my charging fluctuates from the max of 8 kw to 4 kw. It switches back and forth while charging. I haven't noticed this before and wondered if it is just with warmer temps (Upper 80's - 90's in garage) or is my Mobile Charger becoming faulty.

 

[mongo]

I have a Nema 14-50 outlet in my garage and have my Mobile Charging Unit plugged in for charging. Recently I've noticed my charging fluctuates from the max of 8 kw to 4 kw. It switches back and forth while charging. I haven't noticed this before and wondered if it is just with warmer temps (Upper 80's - 90's in garage) or is my Mobile Charger becoming faulty.

I think your S has dual chargers, one may be going bad/ overheating.

 

[Bodyhauler]

The window sticker says my S has a single charger.

 

[F@kegman]

Either the above or the wiring in your home is heating up. To test this theory set you charging limit to something in between 4 and 8kw, like 5. If the lower limit solves the problem then its likely wiring in the house problems. If it still goes down to 4kw and back to 8 then the onboard charger is likely the problem.

 

[F@kegman]

I believe even a single charge has two units inside.

 

[mongo]

I believe even a single charge has two units inside.

Probably. The dual charger was 80 Amp anyway, not 40A so I was off on that.

Either the above or the wiring in your home is heating up. To test this theory set you charging limit to something in between 4 and 8kw, like 5. If the lower limit solves the problem then its likely wiring in the house problems. If it still goes down to 4kw and back to 8 then the onboard charger is likely the problem.

Yeah, UMC will throttle based on temperature.

The vehicle will reduce charge current by 25% current on excessive voltage drop. So it doesn't seem to fit the 4kW/8kW symptom.

 

[Bodyhauler]

The local SC told me it sounds like the UMC is faulty.

 

[mongo]

The local SC told me it sounds like the UMC is faulty.

Maybe, you can also double check that the plug adapter is fully seated (UMC to 14-50 or whatever you are using).

 

[r1200gs4ok]

Maybe, you can also double check that the plug adapter is fully seated (UMC to 14-50 or whatever you are using).

and all wires are securely screwed down.....if the plug is warm or hot you got wiring issues....my Tesla Nema 14-50 was fluctuating between 40kW and 30 kW.....everything was ok ....turned out to be the Tesla charger....it was replaced with a hard wired unit

 

[Bodyhauler]

I had the mobile repair guy at the house today for a handle repair and asked him about the charging unit fluctuating and he told me to make a new repair order and Tesla will bring me out a new UMC replacement free.