Preheating battery behavior changes lately due to software update?

[jrcheesecake]

Not sure if this is due to the latest software update such as 'cold weather improvements', but the battery does not preheat via climate or scheduled departure most of time now. I can still see the snowflake sign even after "preconditioning" for 1 hour! Tested plugged-in or not didn't make any difference.

I found someone posted this on the UK sub-forum, just wanted to check with broader audience.

For me, the temperature to trigger the "preheat" (a.k.a. "the three red lines" on the Tesla App) visually seems much lower now (I am on 2021.40.6). I haven't seen it in the last 2 weeks even when outside temperature (as per Tesla App) dropped as low as 2C. Yesterday (and just once) I saw "the three red lines" again when temp showed 1C. It lasted about 1 minute before disappearing again. Is it just me or a few of us, or is this an expected battery behavior now?

 

[GtiMart]

Yes, there have been changes in "recent" software. Last year, heating the cabin would heat the battery up to 20-21C which was very wasteful for people that do short drives. This year the target heating temperature seems to be in the 4-6C range. I haven't done enough testing to have a definitive temperature but this morning with a battery at 8.5C there was no heating.
At those temperatures you will have some regen but not all of it, you will see some dots.
Another change is in how the car heats the battery. Last year, it would heat the motors red hot, in the 100C range, to heat the battery. Now it seems to only heat the motors a few degrees C over the current battery temp and circulates the fluid in. In my opinion this is much better for the longevity of the motor circuits, plus in general it's less wasteful of energy especially on short drives.

Don't forget that all this logic is around battery temperature, not ambient temperature. You cannot see that temperature unless you have an OBD2 adapter and a CAN bus reader application like ScanMyTesla.

 

[jrcheesecake]

Thanks @GtiMart. It seems like this is an expected behavior then... What it really bothers me is even plugged in, there is no way to heat up battery now if it decides not to.

 

[GtiMart]

I think the car heats the battery a bit higher if you ask it to charge but I need to test more. I normally park in a heated garage so i don't get many opportunities to check that.

 

[jrcheesecake]

In Tesla OEM App, I've tested both "Precondition" under Schedule--->Departure and "Enable Scheduled Charging" under Schedule-->Charge, nothing works to preheat battery . So now most of time, it doesn't preheat...