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 dicembre 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 dicembre 2019

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

bryan.hopkins | 12 dicembre 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 dicembre 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 dicembre 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 dicembre 2019

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

rsrivast | 12 dicembre 2019

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

bryan.hopkins | 12 dicembre 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 dicembre 2019

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

akikiki | 12 dicembre 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 dicembre 2019

Do you have HW3?

akikiki | 12 dicembre 2019

No, '17 with MCU1 and waiting on HW3.

Renzo | 13 dicembre 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 dicembre 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 dicembre 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%

gene | 2 febbraio 2020

I live in a temperate climate, so temperature is not an issue. Since a December 2019 update, regen has not been working as before. When exiting a freeway, I used to simply lift my foot off the accelerator. Now I need to brake hard. Normal driving was nearly one pedal - I didn't need to brake until the car was down to 6 or 7 mph.
Service tech said tapping the brake pedal would cause regen to perform as before, but that doesn't seem to work.
An unwelcome update.

jstowell | 4 febbraio 2020

Unwelcome software update, indeed! Same situation with my '14 P85+...the recent software update lightened the regen braking in a significant way. I live in Northern CA and it is cold out, but I have never had to manually apply the brakes like I have had to in this last month. It is annoying. Ok, Elon & team! Enough already. I already appreciated the regen braking and tell people all the time what an under-rated and under-spoken feature of the car is. I want it back now...PLEASE!

pepsundar | 4 febbraio 2020

2012 MS P85 same problem, noticed significant reduction and increased braking with the recent update.

pepsundar | 4 febbraio 2020

*significant reduction in regen | 4 febbraio 2020

It's temperature related. Get a nice 60+F day, and regen is the same as it always was. Drop down to 55F and you get some regen limitations. If you don't display the energy screen in the instrument cluster, you have no clue if regen is limited or not. I recommend you use it and you'll immediately see any limitations and when the battery warms and it goes away. If I take a lot of very short trips in the cold, the regen limiter doesn't go away, but similar to the way it's always been - just a higher temp threshold.

waynetsouthwell | 4 febbraio 2020

We started experiencing this issue this weekend and notice this get repeatedly dismissed as “weather-related.” Yes, I live in Minnesota with extremely cold weather, at least compared to most of the US, but our regenerative braking worked just fine until Saturday. This is a brand new 2020 car that we have had for 2 very cold weeks. However, since Saturday, having to use the actual brakes for the first time since purchasing the car. Something besides weather is up.

barrykmd | 4 febbraio 2020

waynetsouthwell | February 4, 2020
Something besides weather is up

Obviously. They crippled regen in software and did not disclose it in their "what's new in this update" page that is sometimes blank and sometimes listing important new features such as backgammon.

Conjecture is it's to improve battery life, but we will probably never know for sure.

akikiki | 4 febbraio 2020

TT, we get some 50+F days. And regen is not the same as its always been. It been changed and does not stop the car the way it always has.

Pungoteague_Dave | 5 febbraio 2020 "It's temperature related. Get a nice 60+F day, and regen is the same as it always was. "

Not so. I can never see 60 kw regen anymore - that's never, under any conditions. And the tip-in, which was previously reduced, is now way down (more gradual). Anyway, why should regen limiting happen in the 50's? When it was in the 30's it made sense.

NKYTA | 5 febbraio 2020

Above 50F, my 2012 S still sees 60kW regen.

I'm currently hobbled on supercharging, but that may be something even more than just a software change. I've got to get new pin covers (at the least) in my charge port. | 5 febbraio 2020

@akikiki & @PD - I agree it's been changed, but to me, it seems to only be temperature-related change. At 60+F, I don't see any limitations. At 55F I get about 30 kW regen where that threshold used to start occurring at a lower temp - maybe 50F. I don't get down to freezing to know what happens there. I'll play with it later today as it's below 50F right now and the car is cold soaked. It may be varying depending on the car variant or age, but I suspect it is across the fleet. | 5 febbraio 2020

What makes it a bit more complex is the cars indicated outside temp may not be the battery temp. So when I see 55F outside the battery could be colder. That would explain some of the variances people are reporting.

Pungoteague_Dave | 5 febbraio 2020

I agree, and it could have something to do with battery version. Mine seems more limited than some of the older models. I am current driving a newish Raven MX. One sort of related behavior that I've noted is that regen seems a bit stronger when setting the creep-hold-roll option on stopping to hold. Might be psychological at the low end of the speed spectrum. However, at the higher end speed for accelerator lift-off, the needle never swings past 50 kw regen anymore, and even that's rare. One-foot driving is a thing of the past for us, as it requires such a long drift-down as to inconvenience other drivers - "damn hypermilers!"

barrykmd | 5 febbraio 2020

I still see 60 Kw regen when the battery is warm and the SOC is 50% or less.
PD, have you checked it with a low SOC?

TonyB.C120 | 6 febbraio 2020

I don't care too much about the regen itself. What is a problem is that letting off the accelerator now behaves differently depending on battery temp, ambient temp, and SOC. Whether the regeneration is being sent to the battery or not should not affect how the car responds, IMHO.

Pungoteague_Dave | 6 febbraio 2020

@TonyB, that has always been a feature of regen since the first MS deliveries - I agree it can be a bit disconcerting. Our 2013 MS would surprise me with zero regen every time we'd range charge for a trip. I agree that the driving characteristics of a car should be consistent, and the Tesla's are not, but where would the excess energy go if the car were to use the regular motor's "braking" that relies on a place to send the kw's being generated by that braking.

Pungoteague_Dave | 6 febbraio 2020

@barry, my observation of no regen above 50 kw is at all states of battery charge.

barrykmd | 6 febbraio 2020

TonyB - I used to keep my right-side IC tuned to the numbers (mileage, wh/mi, trip timne, etc). Since Tesla crippled regen, I keep the energy graph on the screen so I know when regen is lacking. Unfortunately, even after driving for a while, there are times when full regen becomes limited regen. I've noticed this on long down hills. Unless you live in a hilly/mountainous rea, that oddity is unlikely to happen to you.

PD - understand. Clearly different recipes for different battery pack versions.

TonyB.C120 | 6 febbraio 2020

@pungo - Excess energy could be shunted into lightening bolts to shoot at cars that do under the speed limit in the left lane.

gene | 12 febbraio 2020

It is definitely not temperature related. I've never had to brake so hard or so often, whether the temperature is 50° or 70° and the amount of charge makes no difference. The unwelcome update completely changed the way the car drives, and for the worse.

wcls | 25 febbraio 2020

Normally, I have right side dash display set on mileage display etc. When regen is off or decreased on its own, the energy graph momentarily shows up with a small yellow triangle at lower right of energy display overlaying the mileage display. When regen goes back to normal more or less, the energy display goes away returning to the mileage display. I live in Southern California where low temperatures are seldom much below 50 deg F overnight and in the morning. My 2019 S long range is kept in garage. The regen is erratic under these conditions but sometimes occur even during the day with temperatures in the 60s. The regen was working fine when I received the car in August 2019. This regen condition occured after an update, I don't remember exactly when. Have to be aware going downhill that regen may not be fully engaged. I never charge above 80%.

Hot Wheels | 4 marzo 2020

I have a 2016 S75 and have also noticed a significant reduction in regenerative braking the last couple months. I was planning to make an appointment with the SC because I thought something was wrong. I didn't put it together with the update until reading this thread. I also realize it happened at just about the same time as the update. One pedal driving is currently a thing of the past.

Webfoot | 12 aprile 2020

I have a 2018 LR M3 and have observed a change in when regenerative braking is turned on for a given ambient temperature. I limit top charge to 70% of battery daily, which eliminates the state of charge as a variable. As far as I can tell, I need to drive longer before regenerative braking is capable of supporting single pedal driving. The change occurred sometime during December 2019. My guess is Tesla is doing this to prolong battery life. I appreciate the intent and have no desire to turn off software updates, but do have to get used to using the brake pedal to come to a complete stop at the bottom of the hill I live on, on a cold morning.

SnowFlake | 12 aprile 2020

@Webfoot we appreciate your opinion. but this is a Model S forum. But wonder why model 3 is affected !!!?

barrykmd | 13 aprile 2020

Maybe we should start calling it Degenerative braking.

Tldickerson | 13 aprile 2020

@barrykmd, that's a good call. It use to work well all of the time.

Elroy Jetson | 14 aprile 2020

I will also confirm that temperature isn't the cause of regen functions becoming limited. It was nearly 80 here yesterday and regen does not function as it used to. Why the cloak and dagger to this unwelcome change?

barrykmd | 14 aprile 2020

Elroy - it will also be limited to 30 kW or so, unless it's only for a few seconds, if your SoC is above 65%.