Keeping battery preheated?

[selfbp]

I’m up a few times throughout the night(s) and was wondering if it would be beneficial to use the new preconditioning battery feature on firmware “.50” for an hour or so throught the night. It’s getting into the 10-20* range in the evenings here now so would it be beneficial to give some warmth in such a middle of the night situation for a little while?

 

[scottm]

Only if you might need to use the car on short notice and you need all the range you can get... say, if your wife is expecting and it's a long way to the hospital.

 

[Ande]

I think of the mandatory battery preheating as a waste of energy.
Parking overnight at <-10°C noes not affect performabce as there is not enough traction to enjoy anything close to ludicrous anyway.
The extra range of preheating battery an hour before does maybe add to range, but on my daily ~25*2km commute I simply don't need it.

Wish battery preheating were optional/selectable in app.

 

[boaterva]

I would say only if you have a planned trip. If you are someone that is on 10 minute alert all night long in subzero weather, just turn Climate to max when you get the word.

And yeah with the weather like this you probably can’t use max power anyway.

 

[AZ Desert Driver]

In days gone by - I stored AAA and D-cells in the fridge to preserve life. I once upon a time stored them in the freezer, thinking "if cold is good, then colder is even gooder". The frozen cells ruptured. Well, I'm no longer clear as to what the damage was, but it for sure was no longer a usable cell.
If a Tesla battery pack was subjected to freezing for a long enough time - would this damage the 2170 cells? Forget about range - I'm asking about irreversible cell damage.

 

[boaterva]

In days gone by - I stored AAA and D-cells in the fridge to preserve life. I once upon a time stored them in the freezer, thinking "if cold is good, then colder is even gooder". The frozen cells ruptured. Well, I'm no longer clear as to what the damage was, but it for sure was no longer a usable cell.
If a Tesla battery pack was subjected to freezing for a long enough time - would this damage the 2170 cells? Forget about range - I'm asking about irreversible cell damage.

So is the final answer that there is no heating of the battery at all until we turn on either the climate (to get battery preconditioning) or actually start using the car/battery?

That seems to be what I’ve seen from all these threads... which means that the battery can’t ‘freeze/damage’ itself from any normal weather we are likely to see.

The other question is, what is actually doing the battery heating when we are running this preconditioning? Is it anything more that the climate heat or is there really heat in the battery coolant fluid warming it up?

The reason for this line of thought are threads mentioning that the climate doesn’t turn off when reaching the set temperature.

 

[William13]

The battery is only at risk for damage at -20 F or so temperature . Not wind chill. I plug it in if it is outside at -10 F or lower just in case. The manual says no concern for a cold battery at -20 F until more than 24 hours ( but it is silent about whether it will use up all its charge self heating. )

It is wasting energy to warm the car or battery in the middle of the night. Even one hour prior to leaving wastes some energy but the car will be nice and toasty and ready to regenerate.

 

[scottm]

I think the "new" battery preheating feechur had always been there all along, just nothing to show its operation until lately they added an icon on the climate page in the App. It was and is always invoked when charging a frozen car, the BMS always gauges temp while determining charge rate and heats in parallel using battery heater to raise charge rate as battery warms.

The newness of this feechur is that turning on climate from App is also now invoking battery heater, if and when and how the car wants, it will sprinkle in battery heat along with your comfort heat. Using this feature without also having the charge cable plugged in is a sure way to reduce range rather than extend it.

 

[Ugliest1]

If a Tesla battery pack was subjected to freezing for a long enough time - would this damage the 2170 cells? Forget about range - I'm asking about irreversible cell damage.

But, the pack's temperature is regulated (i.e. protected) by the software using the energy stored in the pack; the pack won't freeze unless the car isn't plugged in and is left in freezing weather long enough to reduce the stored charge to near zero.

So is the final answer that there is no heating of the battery at all until we turn on either the climate (to get battery preconditioning) or actually start using the car/battery? That seems to be what I’ve seen from all these threads... which means that the battery can’t ‘freeze/damage’ itself from any normal weather we are likely to see.

Well... no heating unless the car feels it needs to keep the battery pack warmer than ambient temperature. Then the car automatically heats the battery whether the owner is there or not.

The other question is, what is actually doing the battery heating when we are running this preconditioning? Is it anything more that the climate heat or is there really heat in the battery coolant fluid warming it up? The reason for this line of thought are threads mentioning that the climate doesn’t turn off when reaching the set temperature.

I can't answer the true technical part (what is it ACTUALLY doing), but from everything I've seen, preconditioning uses energy (from battery, or wall if plugged in) to heat both the climate and the battery, so yes, the fluid is being actively warmed at those times. The climate doesn't turn off? Or the *fan* doesn't turn off? Climate control also reacts when the sun is shining brightly into the car (with a little, but only a little, heat) - by cooling. So I just manually adjust the temp ignoring, almost, the digital number, and what the fan is doing. This is especially noticeable on long trips -- after about 30 minutes of driving, the climate control seems to freeze our legs until we just increase the temp dial.

It is wasting energy to warm the car or battery in the middle of the night. Even one hour prior to leaving wastes some energy but the car will be nice and toasty and ready to regenerate.

Agree totally 10-15 minutes prior to leaving is enough to have the interior toasty, and will also do some battery heating.

The newness of this feechur is that turning on climate from App is also now invoking battery heater, if and when and how the car wants, it will sprinkle in battery heat along with your comfort heat. Using this feature without also having the charge cable plugged in is a sure way to reduce range rather than extend it.

My understanding is, the battery preheating always happened whenever the car's climate was turned on (e.g., via the app), but both would only run for 30 minutes then shut off. Same if driver is in the car; auto-shutoff after 30 minutes of not touching controls. The new feature merely stops the auto-shutoff, but everything else is the same.

 

[AZ Desert Driver]

OK - this says that battery freezing is unlikely. Good to know. But did NOT answer the question - if the 2170 cell WAS frozen, would it be irreversibly damaged? Or, once thawed out and charged, would continue to operate like a battery that was never frozen?

 

[Ugliest1]

OK - this says that battery freezing is unlikely. Good to know. But did NOT answer the question - if the 2170 cell WAS frozen, would it be irreversibly damaged? Or, once thawed out and charged, would continue to operate like a battery that was never frozen?

Not sure why this matters. I definitely don't know. I fully trust that Tesla has designed their cars so that the batteries will not freeze. Don't know what more I can say.