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Regenerative braking reduced warning
- Thread starter jmatero
- Start date
Rshephorse
Member
Parked, not plugged in to charging, turn on climate control in the app, and the battery does heat up- battery inlet temp quickly rises above cell temps, and then battery heats up. This would be worth it if you were driving down from a ski area- to catch all that regen at the start of the trip? It does use around 7.5 to 10.5 kw of juice to do it tho! Obviously best to be plugged in if possible in cold weather; and better yet to capitalize on some of the warming that occurs when charging as well. I guess charge up to a bit before departure and then blitz climate control for the 10-15 minutes before I leave to get the battery temp up into the 70's.....
HeyEph
Member
Is 30mins of pre-conditioning required to get warm enough? I tried 10mins the other day when it was 40deg and this was not enough.
It was 45 degrees in my garage this morning and I pre-conditioned about 15 minutes. Battery temps were ~ 67F when I pulled out of my garage and only 4 dots on the screen. They were gone within 5 minutes.
If you have a few dots on the screen, it's nothing to worry about. The issue is when it's at the halfway, which is when the reduced braking is noticeable.
Rshephorse
Member
I understand that turning climate control on to accomplish preconditioning does difft things at different ambient temperatures. If you are down around freezing it is full-on with battery heating but at moderate temperatures may only heat the cabin. Of course you can fool the system by navigating to a nearby supercharger though to get battery heating even then.
My stators got up to 190 degrees with preconditioning [outside temp 31]. There is a glitch in 'Scan My Tesla" which fooled me. I thought the stators stayed hot even when I turned off climate control - which worried me. Turns out the stators do cool down. You can see this by the immediate drop in power coming out of the battery. What happens through, when stator-heating stop, the car stops sending out the stator temp info in the packet- "Scan My Tesla" just keeps posting the 'last value' for the stator temp.
The whole cold weather management could be a lot more sophisticated. There could be choices for heat cabin, just defrost, heat cabin with defrost, heat the battery, just defrost charging port, and the option to schedule this to happen prior to a departure time with or without scheduled charging....
My stators got up to 190 degrees with preconditioning [outside temp 31]. There is a glitch in 'Scan My Tesla" which fooled me. I thought the stators stayed hot even when I turned off climate control - which worried me. Turns out the stators do cool down. You can see this by the immediate drop in power coming out of the battery. What happens through, when stator-heating stop, the car stops sending out the stator temp info in the packet- "Scan My Tesla" just keeps posting the 'last value' for the stator temp.
The whole cold weather management could be a lot more sophisticated. There could be choices for heat cabin, just defrost, heat cabin with defrost, heat the battery, just defrost charging port, and the option to schedule this to happen prior to a departure time with or without scheduled charging....
Yeah, I don't see that issue. This morning my motors were around 170F peak and about 2 minutes after I started driving, I noticed they were dropping in temp every 15-30 seconds. I typically don't monitor the motor temps; I'm usually looking at the battery inlet temp. As long as that value is greater than the battery pack temp, I know it'll warm up.
Ok, tried again at work (not plugged in) and the motors were ~ 165F and the batteries were 71F (ambient 46F). I don't have an explanation why the previous two times I did the same thing at work the motors were at ambient. Not the most efficient thing to do with each motor drawing 3.5 kW but oh well, it's better for the battery.
Rshephorse
Member
I think there is a temperature, either ambient or battery where the battery heating occurs below it, and does not occur above it.
Back to the original post in this thread...I own a Model 3 and rarely get the reduced regen warning unless it is really cold. Our new Model Y shows this error message much more frequently and the braking is noticeably impacted. Why the difference? Has the battery management system taken a step backward or is it just more complicated now?
I'm very disappointed with the lack of battery warming with the heat pump in the Model Y, compared to what I was used to in my Model 3.
I charged for 2+ hours in my 55 degree garage and left with No Regen Dots (finally). It was 40 degrees outside and I immediately drove for 20 minutes to the store and ended up with 4 dots. I did 2 more quick 5 minute errands at stores (a couple miles of driving in between), and then drove the 20 minutes back home with dots all the way up to the N (10-12 dots). My MY sat in 40 degree temps outside for a total of 10-15 minutes and gained dots while driving 50+ minutes! IMHO, if the regen dots reach the D or go beyond, then regen is basically useless, which is what I will be seeing for the next 3-4 months in Wisconsin.
In this same scenario with my old Model 3, I wouldn't have seen a regen dot the entire time and even if I had started out with dots, they would have gradually disappeared as I drove. With my Model Y, it is the exact opposite.
I charged for 2+ hours in my 55 degree garage and left with No Regen Dots (finally). It was 40 degrees outside and I immediately drove for 20 minutes to the store and ended up with 4 dots. I did 2 more quick 5 minute errands at stores (a couple miles of driving in between), and then drove the 20 minutes back home with dots all the way up to the N (10-12 dots). My MY sat in 40 degree temps outside for a total of 10-15 minutes and gained dots while driving 50+ minutes! IMHO, if the regen dots reach the D or go beyond, then regen is basically useless, which is what I will be seeing for the next 3-4 months in Wisconsin.
In this same scenario with my old Model 3, I wouldn't have seen a regen dot the entire time and even if I had started out with dots, they would have gradually disappeared as I drove. With my Model Y, it is the exact opposite.
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Same experience in colder weather. The Y battery cools down rather quickly if it’s not heat soaked from supercharging or a longer level 2 charging session.
I supercharged 2x in a 6 hr period last week in low 40* temps and the battery had to pre condition for 28 minutes before each session. heat started blowing really hot afterwards. You could tell the battery was warm but it eventually cooled off after driving 2 hrs.
I've seen the acceleration dots already too, which is a bummer as well, since instant, strong acceleration is what makes the car so fun to drive. I rarely saw them in my Model 3, and if I did, it was far colder than it is now...
IMFletcher
Member
Does anyone know why my MY no longer has the ability to change regen braking from Low to Standard!? I hate the low setting! I’ve only had the vehicle since Labor Day, the first 2-months I never had to use the brake, now I have to all the time?
If you Tesla Model Y was purchased after September 2020 there was never an option for Low or Standard regenerative braking, only Standard Regenerative braking. (My Long Range Model Y was delivered in June 2020, has the option to select Low or Standard Regenerative braking.) What you are experiencing, now, as regenerative braking is reduced is due to colder temperatures within the battery pack. You can mitigate this, to some extent, by always preconditioning the Tesla Model Y (especially in the A.M. when the Tesla Model Y has been sitting overnight at colder temperatures.) Depending on the temperature you may have to precondition the Tesla Model Y for more than 15 minutes, even more than 30 minutes in colder weather.
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