Not having regen after the last software update sucks

[SSedan]

Did you know range mode effects the battery heating. Did you by chance turn that on? I see a huge difference in how fast regen comes back if range mode is off. But my wh/mi goes through the roof if it’s off due to battery heating, so I leave it on. You can tell it’s heating on the App Climate page if it shows a red battery icon.

could be they changed when battery heating happens or not when preheating cabin. I don’t know how X behaved last winter because I had Model 3. Which rarely heating the battery (via motors).

Don’t forget SOC charge effects it too. Lower SOC allows more regen.

So again, this is my third winter with this car, car is my daily, lived in the same place the whole time. Have a pretty good handle on how to use it and how it reacts to weather. That said I did verify range mode is off.
Cold weather behavior has definitely changed, my suspicion is it changed with the batterygate and chargergate software updates.
The new scheduled departure makes it easier to leave fairly shortly after it is done though on average it is finishing 30minutes before I leave so I am getting some regen then but 9 hours later nothing on the way home if it is in the teens or lower.

Unlikely to mean anything but the battery heater was replaced 13 months ago.

 

[SSedan]

Hard braking under TACC has absolutely nothing to do with the amount of regen.

Maybe you should get you car services because cruise control has not changed one iota.

I could give a suggestion on how to address that but you just think I’m being a jerk and Tesla has completely borked the software. I’ll let you sort it out.

Statements like you just made is confirmation you have no idea why the car does what it does.

unsubscribing and marking you as ignored.

see ya.

My car predates AP but even I understood the poster you are referring to was saying that with regen limited the car is more often resorting to abrupt application of the friction brakes.

On the broader discussion the lack of regen is a little annoying but not any big problem, my drive is rural/suburban 45mph speed limits. I posted mostly to support those stating there is a change because they are right.

 

[shellderp]

as of a recent update the battery no longer preheats when preconditioning from the app, could that be why you see a difference in regen? When I'm coming out of my warmed apartment garage I don't see any difference, but if I park outside overnight it takes a long time to get it back

 

[PhilDavid]

OMG, you had to use the brakes!! I did too, all last winter. But if I’m on the highway, traffic or no traffic I have AP on and it doesn’t make a damn bit of difference.

Yeah how dare those crazy people who used to have regen now be upset they don't have regen anymore. Right?

 

[PhilDavid]

For those that have noticed the loss of regen, apparently as a result of 2019.40.2.1, how do you explain the results that @Bmac posted (and I quoted) earlier?
In summary, he preconditioned his car and had enough regen for 1 pedal driving. The next day, same weather, he did not precondition his car and he was back to not having regen.

True, it is only 1 data point. However, it seems like a pretty solid example of how preconditioning your vehicle helps to mitigate the regen issue.

Preconditioning (aka warming the battery) is part of the "scheduled departure" feature which IIRC as part of the description says the vehicle needs to be plugged in to work..

Not being a smart@ss. For those that have lost their regen following updating to 2019.40.2.1, I'm curious if preconditioning your vehicle will help to resolve the issue.


And even less if your car is plugged in, so it can precondition itself, while in your 40° garage.

The thing is in past winters after I drove the car around for a while I had full regen. Not having regen was for a short period of time. Now I can complete my entire drive with no regen. This is new and not good.

 

[ucmndd]

The thing is in past winters after I drove the car around for a while I had full regen. Not having regen was for a short period of time. Now I can complete my entire drive with no regen. This is new and not good.

Or maybe it’s new and good. Thanks Tesla for changing Phil’s settings to keep his battery healthy and performing over the long term!

 

[aerodyne]

It would be great if the only result to the alleged Regen nerfing is improved battery health. However, one must consider externalized effects, one of which is reduced fuel economy. Even the lowly Prius classic circa 2002 gets most of it's efficiency in the city due to Regen. In other words, this may well reduce the range and no longer reflect the EPA ratings the car was certified with. Qualitatively, it is like desielgate. Not saying it has the same quantitative effect, or that it was for the same nefarious reasons...

One solution, if your have the option and are still under the power train warranty, is to refuse the 36 - 4O series of updates

 

[Battpower]

Hard braking under TACC has absolutely nothing to do with the amount of regen.

Maybe you should get you car services because cruise control has not changed one iota.

I could give a suggestion on how to address that but you just think I’m being a jerk and Tesla has completely borked the software. I’ll let you sort it out.

Statements like you just made is confirmation you have no idea why the car does what it does.

unsubscribing and marking you as ignored.

see ya.

May be someone else could clarify if tacc / ap use regen & or friction brakes to slow the car. I believe at least ap does, may be not tacc. My observation about unusual braking seeming linked to regen was based on a couple of times where the car applied friction brakes irratically during the period that level of regen was increasing as battery warmed as a result of driving.

Obviously any change in regen behaviour not directly linked to tacc etc.

 

[aerodyne]

May be someone else could clarify if tacc / ap use regen & or friction brakes to slow the car. I believe at least ap does, may be not tacc. My observation about unusual braking seeming linked to regen was based on a couple of times where the car applied friction brakes irratically during the period that level of regen was increasing as battery warmed as a result of driving.

Obviously any change in regen behaviour not directly linked to tacc etc.

On my car, the TACC alone, and with AP, show Regen being displayed on the IC, with max of 50-60 Kw. On rare ocassions, I sense further decel, so I assume brakes are engaged.

 

[Battpower]

the car is more often resorting to abrupt application of the friction brakes.

Exactly.

I was pointing out that it has once or twice felt as though (just like me) ap doesn't know what to expect from regen, especially while it (belatedly) starts working, resulting in choppy application of friction brakes / unsmooth blending between regen and friction.

 

[Battpower]

In summary, he preconditioned his car and had enough regen for 1 pedal driving. The next day, same weather, he did not precondition his car and he was back to not having regen.

Reading posts here, I get the impression that if there is a change in behaviour (regen being limited at higher temps to reduce charge spikes on a 'cold' battery) then it is still likely that precon or warming the battery will help get regen working again.

I see no way of being sure what the underlying real facts are, but the situation feels comparable to if Tesla found Performance models were suffering premature transmission wear, so they found a way of limiting the number of flat out acceleration starts you could make each week / month in order to limit their wty exposure without completely changing the car spec. How you would feel about that as an owner could vary wildly depending on how you chose to view it. (Tesla protecting my transmission vs Tesla's design not up to the job)

 

[Battpower]

As for me, I’ll gladly replace a set of brake pads instead of a battery, and there’s nothing “efficient” about needing to replace a dead battery prematurely.

I can totally agree with that, but I just bought a car based on its regen performance. If I was OK with lower overall energy efficiency, I would have been more likely to go with the I Pace. It really does bring into question the whole process of OTA updates, what is allowed / reasonable / sensible, and what is just the manufacturer back tracking on promises they made to sell product.

 

[Battpower]

this may well reduce the range and no longer reflect the EPA ratings the car was certified with

Yeh.

Do any OTA updates require EPA approval?

 

[PhilDavid]

Or maybe it’s new and good. Thanks Tesla for changing Phil’s settings to keep his battery healthy and performing over the long term!

So are you suggesting something is wrong with the regen profile we have had in the Model S for 7 years from 2012 to 2019 that it necessitates taking away regen in the winter?

 

[Battpower]

Random Google search on cold weather charging:

Fast Charging of Lithium-Ion Batteries at Cold Temperatures :: News :: ChemistryViews

"... in technologies such as electric vehicles. However, the fast charging of lithium-ion batteries, which is necessary for the development of electric vehicles, is only optimal at room temperature. When the temperature decreases (during winter, for example), lithium plating occurs upon fast charging. This drastically reduces battery life and can cause electrical shorts or fires."

 

[PhilDavid]

Random Google search on cold weather charging:

Fast Charging of Lithium-Ion Batteries at Cold Temperatures :: News :: ChemistryViews

"... in technologies such as electric vehicles. However, the fast charging of lithium-ion batteries, which is necessary for the development of electric vehicles, is only optimal at room temperature. When the temperature decreases (during winter, for example), lithium plating occurs upon fast charging. This drastically reduces battery life and can cause electrical shorts or fires."

Yes, we know all this. Regen had worked in the winter for 7 years.

What used to happen is we would not have regen for a short time during the drive in the winter so the batteries can heat up and we would have regen after a brief period of time. Now there is no regen even after 20 minutes of driving.

 

[Battpower]

Yes, we know all this. Regen had worked in the winter for 7 years.

What used to happen is we would not have regen for a short time during the drive in the winter so the batteries can heat up and we would have regen after a brief period of time. Now there is no regen even after 20 minutes of driving.

You don't think it's just a further caution to same issue.? That article just concisely highlights technical issues I thought. Nothing new.

I'm with you though, hasn't effected my other ev's over several years and no issues I'm aware of.

Having a lower soc always helped in the past. I will have to check if lower (say under 50%) makes any difference to Model S. If it does, I could just run at much lower soc.

 

[mhinterseher]

Maybe we are looking at it from the wrong angle. Maybe Tesla is optimizing the overall electric usage / improve efficiency. Reducing regen might sound counter intuitive to being more efficient but if they save energy by not/less heating battery, maybe the overall efficiency increases. I only have a 15min commute with 80% highway, so I can count the number of breaking on one hand. Im not a battery expert but wonder the efficiency loss/gain of driving the way I do with cold battery and reduced regen compared to using precious battery power for heating a 500kg battery for a 15min commute. On top of that knowing that regen is limited makes me drive more efficient as I want to avoid breaking and therefore slow down earlier when not on FSD I’m curious to learn how battery efficiency correlates to temperature compared to energy needed to heat battery to keep battery temperature up. If anybody as a link to an article/diagram would be appreciated. As mentioned earlier 3rd dimension of the diagram is battery life.

 

[SSedan]

Or maybe it’s new and good. Thanks Tesla for changing Phil’s settings to keep his battery healthy and performing over the long term!

Think maybe they should articulate that then? When taken in context with the voltage capping taking away range and probably HP, and supercharging speed reductions with some people seeing peak rate cut in half, again without articulation of what is going on? This looks a lot more like there is a major engineering flaw somewhere they are trying to bandaid it without admitting to anything that would drive a recall. My GUESS is that they were too aggressive pushing the limits of performance of the battery and are scaling back to save their wallet more than my car. Admittedly if there is a major flaw in the system that causes them to NEED to for instance replace all the batteries they have nerfed.............my car would be about worthless because replacing tens of thousands of the affected batteries combined with the marketing damage done by a recall like that would crush the company.

Maybe we are looking at it from the wrong angle. Maybe Tesla is optimizing the overall electric usage / improve efficiency. Reducing regen might sound counter intuitive to being more efficient but if they save energy by not/less heating battery, maybe the overall efficiency increases. I only have a 15min commute with 80% highway, so I can count the number of breaking on one hand. Im not a battery expert but wonder the efficiency loss/gain of driving the way I do with cold battery and reduced regen compared to using precious battery power for heating a 500kg battery for a 15min commute. On top of that knowing that regen is limited makes me drive more efficient as I want to avoid breaking and therefore slow down earlier when not on FSD I’m curious to learn how battery efficiency correlates to temperature compared to energy needed to heat battery to keep battery temperature up. If anybody as a link to an article/diagram would be appreciated. As mentioned earlier 3rd dimension of the diagram is battery life.

That has crossed my mind and I am sure many others but the lack of preheating the pack isn't the only big change. Again when considered with the peak voltage limiting and supercharger rate limiting which is severe it looks like something other than pure efficiency at play in Tesla's decisions.

The other think I think people need to ask is if Tesla was knowingly pushing the limits of battery performance too far for marketing reasons and intend to roll out these kinds of changes as vehicles get to be 5 years old or so?

They need to answer for the changes, I haven't taken my car to my sister's since the updates but between the 15miles they took and I am estimating my charging stop which used to be 50minutes will now be at least 1:15 I don't think I can road trip with the family in it anymore. 50 minutes to go from 10-90 was fine leisurely meal with the wife and kids 1:15 will likely be a deal breaker. Before a koolaide drinker cries about my 10-90% supercharger stop, I am in WI, planning for an extra stop to avoid charging so high means driving 30minutes out of my way on the end where I am close to home, makes no sense. In CA sure you stop more often to avoid the slow part of the charging curve at the top.

 

[Battpower]

Maybe Tesla is optimizing the overall electric usage / improve efficiency.

That would be nice!

Seeing things from different perspectives is very difficult. I think their assumed use case for whatever changes they make is likely to fail to serve many real users.

But if Tesla would communicate, all this conjecture and speculation would not be needed. In my case and some others here by the sounds of it really benefit in efficiency terms from some regen on short (10 mile) journeys. Any amount of preheat / precon needed to preserve regen and recoup a small amount of energy is unlikely to make sense especially on regular short runs. On a longer run, where you need the range and the precon 'cost' might have more benefit, well maybe it makes sense.

It sounds as though posters here understood and were used to regen as it was previously, so ask 'why the change?' I think there is a good case that all these 'gates' are related, and taking a battery lifetime perspective, the energy to be saved from a bit of regen or time saved from faster charging (in Tesla's view) doesn't justify the risks / costs of pushing the battery. Of course that begs the question if Tesla (and others) just promised too high for marketing gain (because they can make enough of a valid argument to support their position) and now realise the cost of trying to deliver on those promises that real owners expect to hold them to. Life is always grey at the margins.

Lithium battery technology has always had a love-hate relationship with temperature. It's just another part of the learning curve I guess as more people have EVs. Finding a way of manufacturers making honest promises for new technologies and products that allow for tweeking in the light of future user experience while deemed to favor neither the customer nor manufacturer is bound to get trickier the further you push the envelope.