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Odd charging issue - Any ideas?

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So figured I would run this by the "experts".

Last night I got home with about 60% SoC, plugged into my Nema 14-50 like always (Had my Model S 85D for about 3 years) and went to bed, the car is set to start charging at 11pm and usually finishes each night at about 4am or so. Now I live in Chicago and this week has been RIDICULOUSLY cold but my car is in a garage thats slightly heated. So that night outside was -11F but the garage was 32. I woke up to see that the car was only at 70%. "That's odd", through the morning it got up to 74% over the course of the 30 minutes I usually leave it to pe-heat so seemed that perhaps the cold had simply slowed my charge time. Concerning but not the end of the world.

Last night I returned home with 41% SoC. The car had sat in -18F all day but pre-heated and drove like a champ. I plugged in at 7pm and noticed the "Snowflake" on the battery logo. No surprise there. Plugged in and decided to manually start charging. I saw 240v and 1/40amp. "Likely the thermal management system warming the batteries first". Out of curiosity I turned on the climate control and saw it jump to 240v, 22/40amps. "So the connector is working and power is flowing. Good". I turn off climate and let the car do it's thing for the night.

A few minutes ago I woke up (5:30am) and noticed that I was still drawing 240v 1/40a, and the battery was at exactly 41% SoC still. Car temp is showing 24F, and have now performed a vehicle reboot (Safety -> Power Off, wait 2 minutes, power back on). As well as rebooted the charger. If I turn climate on I am still seeing 240v 18/40a so power is able to get to the car.

If I take my best guess I have a thermal management problem, the battery was unable to warm back up to the 32F (0C) that is required to start charging, but over the night I would have expected it to be able to achieve this. Plus I drove it home for about 30 minutes (which while it gave me all sorts of low power warnings, still should have warmed the batteries a little). Today is supposed to be -28F so if the cars management can't handle the -18F I have no idea what i am going to do with -28F.

Before I take an Uber to work and schedule an appointment, am I missing anything? Anyone have other ideas?
 
I assume you have taken off the charge start restriction? Which would POSSIBLY start charging when the battery is at it's warmest?? Not sure how a few more hours would make any difference otherwise but, it's the only thing I got, sorry.
 
That does sound to me like your battery heater has stopped working for some reason. You did that very helpful test to see that it can pull power through your wall connection to run the heater in the car, so the supply side is fine. It seems to be waiting for the battery to get warm enough to charge and can't make it warm up.

This may sound ridiculous and take a lot of time and electricity, but you said you have a closed in garage. I'd bet that if you roll the windows down and have the car run the heat in your garage, it could keep using wall power for that, and over the course of several hours, it would get your garage up above freezing, and then the battery probably would begin to charge very slowly at first. Obviously trying to get the battery to warm up just from the air temperature in your garage is going to take many hours, but it could possibly show if that's the issue, but I'll bet you do still have a broken battery heater.
 
So figured I would run this by the "experts".

Last night I got home with about 60% SoC, plugged into my Nema 14-50 like always (Had my Model S 85D for about 3 years) and went to bed, the car is set to start charging at 11pm and usually finishes each night at about 4am or so. Now I live in Chicago and this week has been RIDICULOUSLY cold but my car is in a garage thats slightly heated. So that night outside was -11F but the garage was 32. I woke up to see that the car was only at 70%. "That's odd", through the morning it got up to 74% over the course of the 30 minutes I usually leave it to pe-heat so seemed that perhaps the cold had simply slowed my charge time. Concerning but not the end of the world.

Last night I returned home with 41% SoC. The car had sat in -18F all day but pre-heated and drove like a champ. I plugged in at 7pm and noticed the "Snowflake" on the battery logo. No surprise there. Plugged in and decided to manually start charging. I saw 240v and 1/40amp. "Likely the thermal management system warming the batteries first". Out of curiosity I turned on the climate control and saw it jump to 240v, 22/40amps. "So the connector is working and power is flowing. Good". I turn off climate and let the car do it's thing for the night.

A few minutes ago I woke up (5:30am) and noticed that I was still drawing 240v 1/40a, and the battery was at exactly 41% SoC still. Car temp is showing 24F, and have now performed a vehicle reboot (Safety -> Power Off, wait 2 minutes, power back on). As well as rebooted the charger. If I turn climate on I am still seeing 240v 18/40a so power is able to get to the car.

If I take my best guess I have a thermal management problem, the battery was unable to warm back up to the 32F (0C) that is required to start charging, but over the night I would have expected it to be able to achieve this. Plus I drove it home for about 30 minutes (which while it gave me all sorts of low power warnings, still should have warmed the batteries a little). Today is supposed to be -28F so if the cars management can't handle the -18F I have no idea what i am going to do with -28F.

Before I take an Uber to work and schedule an appointment, am I missing anything? Anyone have other ideas?

Do you have range mode turned on?
 
I think the collective wisdom here says the battery heater uses 5.5 kW, so your 240w draw being plugged in isn't enough. Has your antifreeze been replaced and with the proper (G48 50/50) mix?

One hypothesis... the circulation pump is running and possibly hitting a slush restriction.
Another... you actually have a battery heater failure and so the pumps are running but no heat is being added.

As you noted heat should be added until you get to about 32 degrees, so no surprise no charging occurred.
 
I was having the same issue with my 2016 S70D, eventually after many phone calls and a trip to the SC, they discovered an issue with the battery and are now in the process of a warranty replacement.
I had also thought the issue was related to the battery coolant heater, but Tesla couldn't find anything in the logs to indicate a problem. Then they decided to run the battery diagnostics and just like that they found a problem.
 
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Reactions: Big Earl
Thanks for the feedback and thoughts everyone.
Yes, range mode is off.
Today I left climate on for 4 hours (until it auto shuts off) and checking the temp in the garage got it to 40 degrees. Still no charge. So I will be taking the car in tomorrow morning to see what they can help with as phone support isn't sure what to do. I will share what they find.
 
Thanks for the feedback and thoughts everyone.
Yes, range mode is off.
Today I left climate on for 4 hours (until it auto shuts off) and checking the temp in the garage got it to 40 degrees. Still no charge. So I will be taking the car in tomorrow morning to see what they can help with as phone support isn't sure what to do. I will share what they find.
Any updates on this?