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Cold Temperature Battery Maintenance

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I wish there was a way to tell the car to maintain the battery temperature while plugged in. I can't imagine it would take much power, and properly maintaining something that expensive is totally worth it.
I bet it would take far more than you realize. Think about how much faster the battery drains when you’re heating the cabin or using the heated seats and as long as the coolant doesn’t freeze there‘s really not much benefit. Your power may be a bit reduced, but if It’s that cold you shouldn’t be driving that hard anyway.

I’ve gotten in the habit of opening the app and hitting the climate/fan button when I’m done at work. The cabin is warm by the time I get to my car and the battery’s also been warmed up.
 
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If the car is not plugged into shore power, the traction battery is never actively heated; however, it will wake up to top off the 12V battery about once a day. This 12V top-off will create some residual heating due to the systems that are needed for this function such as coolant pumps, PCS board active, etc. At temperature extremes the battery will probably not warm even 1F.

When plugged in, the battery does not technically actively heat the battery but it does indirectly. When the traction battery charge level drops to some percentage below the user set charge level (this was 3% but may have changed), the car will wake up to top off HV traction battery. Note: Depending on the power draw while sleeping, it could take several days to drop this 3% which could be a problem in extremely cold temps. If the HV battery is not warm enough to accept a charge (last time I checked the HV battery cells were heated if below about 46F), the HV battery cells will be heated to a point where they can accept a charge.

So if you charged the HV battery to 90% and then set the charge point back to 50%, the car would not need to top-off the HV battery for probably a few weeks. During this extended period the HV battery would not require a charge and therefore could become cold soaked to the ambient temperature. If that temperature was below -22F, this could be problematic!

I have never read anywhere where the car will attempt to warm the HV battery when exposed to cold below -22F for over two days (to stave off possible permanent damage).

If any of the above is incorrect or has changed please respond to this thread. Some things could differ from my 2018 Model 3. The Model Y does have a heat pump and it can be used to heat the traction battery; however, at temps below -15F, the HV battery heating is probably performed the same way as my Model 3 by sending current through the motor stator windings.

Regards..