Cold battery will not charge (-20C / -4F)

[Thunderstrike44]

I saw this article yesterday, thanks to this group! I experience the Regen Braking all the time when temps drop below 10°F. As far as charging my CT is in a garage but unheated and uninsulated so it still get pretty cold. Again thanks to the group hear if its below 10°F in the garage I schedule a Precondition in the app 1/2 hour before I start the actual charge and have had no issues so far . The responses I see here are all valid so far, and if you tried all those maybe try the supercharger suggestion. I got my CT 3 days before thanksgiving and its been cold the whole time I have had it. My snowflake has only disappear twice since I have had it, I wouldn't overly pay attention to it. You are in a colder environment than me right now, so you might be seeing things the rest of us have not. We are all test subjects here as early adopters. I am Glad we have each other for support!

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[NICKEM]

Responses so far seem to miss the point. I will come home late afternoon, plug in my CT and charging is programmed to start at 11 pm, when the power price is the lowest. By morning my CT normally is fully charged, ready for the day. The past few days it has been quite cold. -20C (-4F). This means that by the time the car starts to charge, the battery is very cold. Under those circumstances, the car will not charge and throughout the night will show a draw of 2A, rather than go through a phase of heating the battery and once battery is heated up continue to charge at 40A.

I would start charge earlier in the evening. Yeah it will cost a little more for the first hour or two, but seems like it might be better than having no charge when you get up in the am.

 

[RickB]

My CT is programmed to start charging at 11 pm, when off peak rates apply. During a recent cold spell, the temperature at night dropped to -20C (-4F). My charger is a Tesla, gen 3 charger, 240V, 40A. When the car is sitting at these low temperatures, when charging is initiated it will draw 2A, while showing "battery is heating up" message. This 2A current however is not sufficient to heat the battery and as a result the battery will not charge at all. Under all other conditions, charging, pre-heating passenger compartment, etc., everything works as intended. The only time the car will not charge is with the battery at such a low temperature. I personally believe it is a software setting in the car, which prevents sufficient current to be drawn to heat the battery for charging to eventually start. Right now in a cold night, the car will sit there and draw 2A throughout the night, without any capacity being added to the battery itself. Would be interested to find out if others have a similar experience.

I experienced the same issue this past weekend up at our condo in the mountains. Truck stays outside with a Level 2 charger connected. Truck was cold when it was plugged in at about 7pm with 42% battery charge. Temps dropped to 8 deg F. Went out at 8am and battery was still at 42% charging at 2A. Disconnected and reconnected charger and still sat at 2% for the next two hours. I decided to take a 10 mile drive, came back and plugged in the charger and it started charging at 32amps which is the max for my 40A breaker (80%).

 

[Jhodgesatmb]

My CT is programmed to start charging at 11 pm, when off peak rates apply. During a recent cold spell, the temperature at night dropped to -20C (-4F). My charger is a Tesla, gen 3 charger, 240V, 40A. When the car is sitting at these low temperatures, when charging is initiated it will draw 2A, while showing "battery is heating up" message. This 2A current however is not sufficient to heat the battery and as a result the battery will not charge at all. Under all other conditions, charging, pre-heating passenger compartment, etc., everything works as intended. The only time the car will not charge is with the battery at such a low temperature. I personally believe it is a software setting in the car, which prevents sufficient current to be drawn to heat the battery for charging to eventually start. Right now in a cold night, the car will sit there and draw 2A throughout the night, without any capacity being added to the battery itself. Would be interested to find out if others have a similar experience.

No that is the way it is designed to work. It will not charge the batteries until they are warm. You may have to charge during higher-rate times, go for a drive, or navigate to a supercharger. Even then, if your battery doesn't reach precondition temperatures, your battery will charge at a super low rate.

 

[Crissa]

No that is the way it is designed to work. It will not charge the batteries until they are warm. You may have to charge during higher-rate times, go for a drive, or navigate to a supercharger. Even then, if your battery doesn't reach precondition temperatures, your battery will charge at a super low rate.

And certainly it should know the weather and temperature and select a more appropriate heating solution based upon these constraints.

In fact, at a certain point, it's more electrically efficient to heat faster, charge faster, on Level 2.

So also, no, it's supposed to heat itself up too slowly.

Something can be 'working as designed' and still not right. That's why Tesla can do over the air updates for this sort of thing. They'll fix it eventually. At least, they have historically.

-Crissa

 

[trentsize]

No that is the way it is designed to work. It will not charge the batteries until they are warm. You may have to charge during higher-rate times, go for a drive, or navigate to a supercharger. Even then, if your battery doesn't reach precondition temperatures, your battery will charge at a super low rate.

As stated several times above, it’s a bug already acknowledged Tesla to be fixed in 2025.2.

 

[trentsize]

This happened to my truck again last night for the first time since the fix came out. Anybody else? I scheduled charging to start at 12AM, and it stayed at 2A for two hours before I had to go out to navigate to a supercharger to heat the battery. It started charging full power again after that. I’m on 2025.45.8

 

[HaulingAss]

Heating a cold-soaked pack is like defrosting a 1000-lb steak. It's gonna take a minute.

Be glad the battery is not like the big batteries in GM electric truck products. Owners are finding out the disadvantages of such large batteries (and inefficient thermal management system) in terms of time to pre-heat the battery, slow DCFC in cold weather when the battery cannot get warm enough quickly enough, and extra high electrical consumption when the mercury drops. A battery that weighs twice as much has twice as much thermal mass to overcome whenever the BMS needs to adjust the temperature of the battery.

Tesla had the experience to know that battery size is not a matter of "the bigger, the better", it's all about having enough. For practical reasons there are big negatives associated with a battery so big that it never gets even 70-80% used.

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