Charging dropping to 9a from 48a

[Tanner Dunkel]

I've noticed a couple of times recently that my model 3 will be charging at 9A in the morning after I set it to precondition and warm up and that the wall charger will be green with a single red LED at the top. Looking online this appears to be overheating but every part of the charger is cold (and its below 0°c in the garage where the charger is and by the car).

Anyone know why this may happen? It is within a few percent of my 90% charge limit typically but I'd like it to stay at 90 before my drive. Like I said, it usually happens when it's set to precondition or if I set it to defrost car.

 

[Prodock]

I had a similar issue a couple times when I used a mobile charger (before installing a wall charger). The first case was the electrician didn’t install a high quality 14-50 receptacle the second time it went away after I cleaned the charger end and car port with a q-tip and alcohol. I got some black crud out, I’m not sure that was really the issue but I never had that happen or the overheat alarm again. I haven’t had it since installing the wall charger about a year ago either.

 

[LoudMusic]

Could be overheating at the wire. It would be a good idea to turn off the breaker and make sure all the screws that clamp wires down are sufficiently tight.

 

[rpiotro]

Could be overheating at the wire. It would be a good idea to turn off the breaker and make sure all the screws that clamp wires down are sufficiently tight.

And in the wall charger.

Those items actually have a torque specification. Generally about 50 inch-pounds. You can use a tool like in the link. I have a 3/8" drive torque wrench in in.-lbs. With some adaptors I can torque those screws correctly.

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[Tanner Dunkel]

And in the wall charger.

Those items actually have a torque specification. Generally about 50 inch-pounds. You can use a tool like in the link. I have a 3/8" drive torque wrench in in.-lbs. With some adaptors I can torque those screws correctly.

Fastener Island: Best Torque Screwdrivers of 2022 - Gear Hungry

For tightening fasteners according to spec, the best torque screwdrivers are the right tools. Here’s our guide to the best in 2022.

www.gearhungry.com

I installed myself and torqued the wires to spec.

It only seems to happen when preheating the car in the morning and even then, only occasionally

 

[ATPMSD]

I have to agree with @rpiotro as the connections in the Wall Connector may have become loose. This is an all too common problem and easy to fix. They need to be torqued to 50 lbf . in (5.6 Nm).

 

[Sorny]

I've noticed a couple of times recently that my model 3 will be charging at 9A in the morning after I set it to precondition and warm up and that the wall charger will be green with a single red LED at the top. Looking online this appears to be overheating but every part of the charger is cold (and its below 0°c in the garage where the charger is and by the car).

Anyone know why this may happen? It is within a few percent of my 90% charge limit typically but I'd like it to stay at 90 before my drive. Like I said, it usually happens when it's set to precondition or if I set it to defrost car.

It's likely done charging and the draw you see is to run the HVAC to maintain the precondition temp of the cabin.

My car routinely completes charging 30-45 minutes before the scheduled departure, and then sits and starts drawing current to precondition the cabin.

I see anywhere from 5-12A of current draw while preconditioning; much more if the car is set to defrost.

 

[UncleCreepy]

It's likely done charging and the draw you see is to run the HVAC to maintain the precondition temp of the cabin.

OP mentioned a red light on the Wall Connector, though. While you are right about a lower amperage draw while preconditioning, OP's problem appears to be something else. As far as I can tell, @rpiotro and @LoudMusic got to the bottom of the problem.

 

[Sorny]

OP mentioned a red light on the Wall Connector, though. While you are right about a lower amperage draw while preconditioning, OP's problem appears to be something else. As far as I can tell, @rpiotro and @LoudMusic got to the bottom of the problem.

Good catch, I totally spaced the red led bit...

 

[ucmndd]

Looking online this appears to be overheating but every part of the charger is cold (and its below 0°c in the garage where the charger is and by the car).

No surprise that everything is cool at 9 amps. That’s why the car is reducing the amperage in the first place, to get to a safe current level and avoid overheating.

You need to figure out what’s getting hot after a sustained period of charging at 48 amps.