Regenerative braking reduced with 2019.36.2.1.ea322ad

Regenerative braking reduced with 2019.36.2.1.ea322ad


I noticed that the regenerative braking has reduced significantly. prior to the update, removing my foot off the gas pedal - would very quickly bring the car to a slow halt.. I never used the brakes.. now I see that regeneration happens rather over a period of distance.. It works - but not as aggressive.

not sure - if anyone else is seeing this. I have not changed my settings. I would like to get back to the rather aggressive setting - of slowing down the car and not have to use the brakes.

thanks -

PrescottRichard | 25 novembre 2019

This *could* very likely be due to the weather getting colder. What are your morning temps outside?

Pull up the display that shows you the energy consumption live and see if you have yellow dashed lines at the bottom of your regen area. If so, that’s what is going on.

If not, I dunno. It’s in your head :)

FWIW- The car will warn you about lost regen just as it does when you are charging over 90% by flashing that display in your ‘instrument cluster’ display.

If this is stuff you already know, I will apologize ahead of time but you didn’t mention checking this display so I’m guessing you haven’t looked.

srisitar | 25 novembre 2019

thank you - yes.. I did see that yellow dashed line - but I see this issue in the morning when temps are low.

but I expected the issue to be resolved by the afternoon - where the temps during the day are normally around 70+. I live in the bay area - sunnyvale..

but I guess you have given me something to look and evaluate more.. thanks

PrescottRichard | 25 novembre 2019

Happy to help! Sounds like a nice place. I’m in the mountains of AZ and we are getting some chilly weather this week.

That’s the kind of thing that catches people off guard all the time.

john.trapp | 28 novembre 2019

I have experienced the same problem, and now have to use the brakes a lot more. Very frustrating, and it reduces the range of the car.
It first occurred after the latest software update, but also the weather had turned colder. I talked to Support and they said that coldness was the reason, but I am not convinced. The software has changed; there never used to be a dashed line on the regenerative part of the Energy display,

Bighorn | 28 novembre 2019

The dotted yellow line has existed for years. It’s the cold.

egonzo21 | 12 décembre 2019

Definitely something to this........both myself and my wife downloaded 2019.36 on Weds. Her in the morning and I in the afternoon. Its been in the 30s here in Texas for the past couple of days. So this was a great side by side comparison. On Tues Morning when we drove in prior to 2019.36, we preheated our cars as always for about 30-45 mins, and just like always we had the regen limiter dotted yellow line indicating limited regen due to a cold battery. This usually drops off when the battery is warm enough to take full regen, for us that is about the midway point of our after we downloaded 2019.36 (we both have classic's 2013 and a 2015) we preheated our cars just as always. When my wife drove in yesterday morning she said her regen (the dotted yellow line was present) was limited her entire drive in, it only fell off as she was exiting to her office. I thought it was nothing (which it still is), however this morning when I drove in, I also noticed that my regen was limited (yellow dotted line) for my entire drive in. I should note that I even preheated the car for a bit longer this morning than usual knowing it was 34 degrees out. Anyways, long story short I think Telsa may have tweaked our battery regen limiter on older cars with that software upate. No doubt it is a safeguard for the battery. Just thought I'd share as I experienced this on my drive in just now.
Have a great day everyone!

egonzo21 | 12 décembre 2019

and yes the yellow dotted line has existed for quite sometime as BH noted.

bryan.hopkins | 12 décembre 2019

@egonzo21 -- thanks for the information. Been noticing my battery has been limited also here in MI where it is in the low to mid 20's. Last year, by the time I would get to work (22 mile drive) the battery would have warmed sufficiently that the yellow would disappear. The last several days, I get to work and only a bar or two disappear, but I'm still left with limitations. As a test, I set the car up for scheduled charging using my departure time this morning. Charging kicked off at 04;30 and finished at 05:44 (charged to 90%). Car then proceeded to pre-heat starting at 05:55 and continuing to heat until I left at 06:17. What's interesting, according to Teslafi, the battery heater was NOT on during the pre-heating time. Battery heater was reported as being on from 04:31 - 04:41. Looking back over the last few days, battery heater doesn't seem to be on very much, surprisingly so. Definitely seems to be a significant change from last winter.

As a note, 2015 MS, 85D here, SW version 2019.36.2.7

Bighorn | 12 décembre 2019

It could be related to what you’re plugged into. If the battery heater draws 6 kW and the cabin heat draws 6 kW, most people are not set up to do both simultaneously.

egonzo21 | 12 décembre 2019

Okay so there has most certainly been an adjustment. I just got back from running errands and lunch. I was out driving for about 40 mins, in highway speeds, heater on. and I had a limited 30kW yellow dotted line regen for the entire time. Its 55 degrees out, hardly cold. No way has that ever happened before as I would have noticed. So I'd say in the new update something was tweaked regarding the BMS. 1st world problem I know, but still kind of annoying. I hate using m brakes now. oh well just thought I'd add my most recent experience.

rsrivast | 12 décembre 2019

check is range mode - does lazy battery conditioning is on.

rsrivast | 12 décembre 2019

sorry phone typing is still not easy: check if range mode - does lazy battery conditioning if on.

bryan.hopkins | 12 décembre 2019

@bighorn, car was plugged into a 50amp circuit and car set to pull 40 amps. Again, I think something has changed in the software. Last year, equivalent temps, driving to work, 22 miles, battery would be warmed up by the time I arrived even without pre-conditioning This winter (and we haven't even hit the bitter cold yet), battery is never fully warming. I'm starting to wonder if perhaps the software change was only for a subset of cars.

bryan.hopkins | 12 décembre 2019

@rsrivast - double-checked and range mode is off.

akikiki | 12 décembre 2019

I got 40.2.1 today. Drove right after it was installed. The damn car now sees traffic lights !! Amazing. On the instrument panel, the lights even turn from red to green matching the real lights. Wow. I was sitting on a four lane road with a left turn light. The car saw all three traffic lights in front of me. It did not show the one to my left, the left turn lane light change from red to green arrow. Just faded from red to nothing light up. But both in front of me were red then green within a second with the real lights changed. Wow.

Bighorn | 12 décembre 2019

Do you have HW3?

akikiki | 12 décembre 2019

No, '17 with MCU1 and waiting on HW3.

Renzo | 13 décembre 2019

I wonder if this has to do with the year of your car, rather than any temperature change. I have a 2013 Model S and my regen when I let go of the accelerator goes to 60 kW (the green line). I got a loaner last week that was a 2015 model S while my car got some warranty work done and when I drove it I noticed that the regen was not as strong as my Model S. When I looked at the energy graph I noticed that on the 2015 the regen would only go to 50 kW when I let go of the accelerator and then tapered down as I slowed down, but it never regen-ed to higher kW than 50. For the record I live in South Fl, so I have no low temps to interfere with regen (in the year that I have had my car, I have only seen the yellow dotted line twice, so I am aware of its existence. I wonder if update 2019.36.x.x changed the max regen setting for newer cars? My 2013 is on 2019.40.2.1 and it regens to 60 kW

egonzo21 | 13 décembre 2019

my max is still 60 KW. on my 2013 was just yellow line limited from 15-30KW. While I still think some minor BMS tweaking was done for colder weather with the 2019.36.1 update. I did as BigHorn suggested in another thread and started to charge in the morning, while I had the cabin preheating. It also was a little warmer today at around 44 degrees F. All that to say my regenerative braking was only limited for the first 1/2 of my drive like normal (yellow dotted line) this morning. So I'll just get in the habit of giving my S a little juice on cold mornings to help wake her up!

reed_lewis | 13 décembre 2019

@akiki - Welcome to the club. I have a late 2016 Model S with Hw 2.0 also. I wonder what the upgrade path will be to 3.0

As to regen, remember when the battery is cold, the regen will be significantly less than normal. My S if it is cold in the AM has basically no regen at all. It is kind of like when the battery is at 100%