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2022 M3LR Insufficient Regen After Preconditioning

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Kandiru

Active Member
Oct 20, 2014
1,774
815
USA
With the cold weather my veteran Tesla driver reflexes kicked in and turned on cab heating to 70F 30min before leaving from work.
Interestingly, unlike in my old MS, the M3 low regen icon remains on and regen is subpar. After two days, I went to 45min preconditioning
with same result, regen braking there but subpar.

What is wrong here, defect or normal with heat exchanger cars? Anticipated thanks to all.
 
Currently around -3°c, 0°c (32F) battery... no regen at all... (SMT says also 0kw regen available..) after 1-1.5km regen stars to work little bit.. is this some sort of bug?(2022.40.4.1) I cant remember that it was like this last winter..
 
I remember reading (Dont think it was official Tesla) that it was taking more energy to warm up the battery than regen was capturing. So might as well not waste the energy.

I wish I had more regen when its cold, so I have been keeping the car below 60% and its pretty good during the cold temperatures.

This winter, I dont see my car heating the battery anymore during preconditioning. So I guess they skip it now.
 
Simply turning Climate on will not pre-heat the battery. Your cabin will be nice and toasty, but your pack is still cold as ice.

The only way I know to actually pre-heat the battery is to go into Scheduled Departure and activate the "Precondition" button (along with an appropriate departure time, of course).

In the OP's first example, of a 30-minute-from-now departure, from a ~30F ambient, cold-soaked temperature... the stator(s) will draw current immediately and quickly rise in temperature (well north of 100F in just 2-3 minutes). In an AWD Model 3 (front and rear stators), this will raise pack temp ~10F in the first fifteen minutes; and about another 5F in the fifteen minutes after that.

This as of 2022.40.4.1. Subject to change as Tesla tweaks their algorithms, of course.
 
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...The only way I know to actually pre-heat the battery is to go into Scheduled Departure and activate the "Precondition" button (along with an appropriate departure time, of course)...
Phucked up cuz you can only set it up to do it on a schedule weekday or weekend, no pushbutton precon option. I might just do this until they wake up and fix it 4 years from now.
 
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Set my car to be ready today (2022 Model 3 Performance with heat pump) and it doesn’t appear to have warmed the battery. Checking my wall connector energy usage, it only pulled 1kW for about five minutes before it said the car was ready.
 
Set my car to be ready today (2022 Model 3 Performance with heat pump) and it doesn’t appear to have warmed the battery. Checking my wall connector energy usage, it only pulled 1kW for about five minutes before it said the car was ready.
Regaj spoke da truth:

Simply turning Climate on will not pre-heat the battery. Your cabin will be nice and toasty, but your pack is still cold as ice.
 
With the cold weather my veteran Tesla driver reflexes kicked in and turned on cab heating to 70F 30min before leaving from work.
Interestingly, unlike in my old MS, the M3 low regen icon remains on and regen is subpar. After two days, I went to 45min preconditioning
with same result, regen braking there but subpar.

What is wrong here, defect or normal with heat exchanger cars? Anticipated thanks to all.

The battery heating target temperature during preconditioning has been reduced in recent years. It will never fully restore regen. In my experience, battery heating stops after 10 to 15 minutes, so preconditioning for longer than accomplishes nothing other than wasting energy.

The only major benefit to preconditioning the battery is to put some heat into it in preparation for a long trip. This will restore energy that was unavailable due to cold temperature and also somewhat reduce the amount of energy required to precondition for your first Supercharger stop.
 
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Regaj spoke da truth:

Simply turning Climate on will not pre-heat the battery. Your cabin will be nice and toasty, but your pack is still cold as ice.
Sorry that I wasn’t clear. I told the car to be ready via scheduled departure. So even that doesn’t warm the battery anymore.

Of course the car was in a garage that was ~50°. So maybe if it was colder it would have been warmed.
 
Heating the cabin WILL also condition the battery, IF it is cold enough. The exact same happens with scheduled departure. The target temperature has changed over time. Currently I believe it is around 7C, which will provide good regen (say 50kW) but not full (85kW). From memory (but I will double-check when I have time and condition here) at 0C battery you don't get any regen.

EDIT: I should say that my numbers are on a 2020 LR AWD model 3, so the old battery (not LFP), at around 50% SOC.
 
Heating the cabin WILL also condition the battery, IF it is cold enough. The exact same happens with scheduled departure. The target temperature has changed over time. Currently I believe it is around 7C, which will provide good regen (say 50kW) but not full (85kW). From memory (but I will double-check when I have time and condition here) at 0C battery you don't get any regen.

EDIT: I should say that my numbers are on a 2020 LR AWD model 3, so the old battery (not LFP), at around 50% SOC.

What I can say is that on a 2022 Model 3 LR AWD, running 2022.40.4.1, ambient temp of 30F, and a cold-soaked pack at 37.4F... heating the cabin most emphatically does NOT heat the battery. Front and rear stators remain quiescent and pack temp does not change, even as the cabin warms.

As soon as you activate "preconditioning," under Scheduled Departure (30 minutes from now), the stators immediately draw current, their temp rises well north of 100F, and the pack begins to heat.

I suppose it's possible that at some temperature simply hitting the Climate icon will also trigger pack heating. But I'm doubtful. Lithium plating is certainly a thing at 30F and if Tesla believed it desirable to heat the pack at some lower temp - say 10F - they would also do it at 30F.

Absent evidence to the contrary, I'm inclined to think that cabin heating is... just that.

Now regenerative braking no doubt has several factors at play beyond pack temp. So it's quite possible to have a perfectly warm battery and still have less-than-expected regen.
 
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Required temperatures have been reduced for lots of things. Also, someone can correct me(with data please, R/F power, not "max regen" in SMT) if I am wrong but didn't Tesla recently limit max regen to around 65kW? I thought I had read that somewhere on here. I haven't been able to take that data yet to check it on my car.
 
What I can say is that on a 2022 Model 3 LR AWD, running 2022.40.4.1, ambient temp of 30F, and a cold-soaked pack at 37.4F... heating the cabin most emphatically does NOT heat the battery. Front and rear stators remain quiescent and pack temp does not change, even as the cabin warms.

As soon as you activate "preconditioning," under Scheduled Departure (30 minutes from now), the stators immediately draw current, their temp rises well north of 100F, and the pack begins to heat.

I suppose it's possible that at some temperature simply hitting the Climate icon will also trigger pack heating. But I'm doubtful.
I did a test just for you while leaving the office today. Outside temperature was -6C (21F). As soon as I started heating the cabin from the mobile app, the car started heating the battery, ScanMyTesla showed 3kW being burned at each motor, they were heating up, the battery inlet was warming etc, My battery was at 0C (32F) min - 1.5C (34.7F) max. Now here's the fun part : as soon as I opened the car door, the motors went down to 0kW, the car stopped heating the battery. This might be why some people are misled to believe the car will not heat the battery. You have to stand outside the car in the cold to check ScanMyTesla to see this happen.

At that temperature I had zero regen. I started to get a little bit of regen (6kW) while driving with my battery still at 2C but I stopped for a quick errand. When coming back outside, regen was down to 0 even though the battery had not apparently cooled down. Regen started creeping up again as I was approaching home. I had 13.3kW max regen with my battery at 1.5-2.5C. As indicated in another thread, regen is not just about battery temp, it also depends on how you drove just before.
 
I did a test just for you while leaving the office today. Outside temperature was -6C (21F). As soon as I started heating the cabin from the mobile app, the car started heating the battery, ScanMyTesla showed 3kW being burned at each motor, they were heating up, the battery inlet was warming etc, My battery was at 0C (32F) min - 1.5C (34.7F) max. Now here's the fun part : as soon as I opened the car door, the motors went down to 0kW, the car stopped heating the battery. This might be why some people are misled to believe the car will not heat the battery. You have to stand outside the car in the cold to check ScanMyTesla to see this happen.

Interesting results there, @GtiMart. Thanks for running that test. Looks like Tesla makes a distinction between behaviors of driver-is-in-the-seat vs. just-got-remote-signalled-via-the-app-to-precondition.

In any case, the context for preconditioning is that the driver is NOT in the seat. I'm opening the app a few minutes before I'm heading out and asking the car to heat the cabin and start heating the pack. Alas, simply hitting the Climate icon fails to do the latter. Which is too bad, because for me heating the pack is far more important than heating the cabin.
 
But that's what I did @Regaj, open the apps a few minutes before leaving and asking to heat the cabin. That does heat the battery until I open a car door. I did it again this morning with outside temp of -4C after the car slept outside all night. Here's a screenshot just a little bit after starting cabin conditioning:
1669123941496.png

And another one a few minutes later, just before I went out to leave:
1669123980089.png


You can see that power goes up to 3.5kW per stator after a while when cabin heating pulls less power.

I have a 2020 LR AWD Model 3, so resistive heating (no heat pump) in case that makes a difference.
 
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But that's what I did @Regaj, open the apps a few minutes before leaving and asking to heat the cabin. That does heat the battery until I open a car door. I did it again this morning with outside temp of -4C after the car slept outside all night. Here's a screenshot just a little bit after starting cabin conditioning:
View attachment 877126
And another one a few minutes later, just before I went out to leave:
View attachment 877127

You can see that power goes up to 3.5kW per stator after a while when cabin heating pulls less power.

I have a 2020 LR AWD Model 3, so resistive heating (no heat pump) in case that makes a difference.

Your test results mimic my own experiences in my 2018. Were you plugged in or unplugged? If plugged in, could you please repeat the test with it unplugged and see if you get different results?
 
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Your test results mimic my own experiences in my 2018. Were you plugged in or unplugged? If plugged in, could you please repeat the test with it unplugged and see if you get different results?
I still think the temperature targets are different. My car used to heat the battery in the past when it was below 50F. Now I dont hear the motors running anymore when in my garage and remote started.
 
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