Who has lost regen with winter tires?

[pcons]

Regarding the questions whether a model 3 does blended Regen braking and if EAP uses friction brakes it is No, Yes.

Model 3 doesn't do blended Regen. Ie the brake pedal is just a brake pedal. This was confirmed by the sales guy during my test drive, but you can also easily confirm it yourself. Put the car into low Regen and lightly press the brakes at pretty much any speed. The Regen bar does not increase when you do this. In a car with blended Regen like a volt or Bolt when you lightly press the brakes you do indeed see the energy going into the battery increase.

Regarding EAP using brakes, it 100% does. Otherwise EAP wouldn't bring you to a full stop (which Regen doesn't do on the 3).

 

[La Piazza]

I'm here in California with just cool weather & no snow at all. We have both a RWD & AWD Model 3 with factory provided aero wheels. For the past few weeks we have been getting, "regenerative braking limited" messages as well as dots showing the limited regenerative braking for both vehicles. I have been SUPER curious as to why this is happening. I cannot figure out the pattern... it is not always when the motor is cold and it definately is not because I charged mor than 80%. It seems random and I cannot figure it out. It really hasn't interfeared with my driving I just want to know why!

 

[fidodido]

I'm here in California with just cool weather & no snow at all. We have both a RWD & AWD Model 3 with factory provided aero wheels. For the past few weeks we have been getting, "regenerative braking limited" messages as well as dots showing the limited regenerative braking for both vehicles. I have been SUPER curious as to why this is happening. I cannot figure out the pattern... it is not always when the motor is cold and it definately is not because I charged mor than 80%. It seems random and I cannot figure it out. It really hasn't interfeared with my driving I just want to know why!

There are couple of reasons why model 3 goes into limited regen. Tlyou shouldn't be charging the battery when the battery temperature is low. As it's harmful to the battery. It needs to get warm enough to start charging the battery The other reason might be the safety. If full regen kicks in on slippery surface, it might lose the traction and skid.

 

[mociaf9]

Regarding the questions whether a model 3 does blended Regen braking and if EAP uses friction brakes it is No, Yes.

Model 3 doesn't do blended Regen. Ie the brake pedal is just a brake pedal. This was confirmed by the sales guy during my test drive, but you can also easily confirm it yourself. Put the car into low Regen and lightly press the brakes at pretty much any speed. The Regen bar does not increase when you do this. In a car with blended Regen like a volt or Bolt when you lightly press the brakes you do indeed see the energy going into the battery increase.

Regarding EAP using brakes, it 100% does. Otherwise EAP wouldn't bring you to a full stop (which Regen doesn't do on the 3).

I think what is confusing people is that they have to lift off the accelerator to press on the brake pedal. So, as soon as they lift off the throttle the car will start regen braking. Then they add to that amount of deceleration from regen with the friction brakes by pressing on the pedal. I believe this "addition" only happens up to the point where the friction brakes are slowing you down more than whatever the top limit for regen deceleration is. So, in the end, it's not that depressing the brake pedal itself is causing blended regen braking. It's just an artefact of how each pedal operates independently. But because the action happens in quick succession and/or they aren't paying attention to the regen bar during the exact sequence of movements, it feels/looks like pressing the brake is causing some regen.

 

[La Piazza]

I didn't know about refraining from charging when the battery is cold. Where did you learn about that? And does it mean one should heat the car before charging? Will the car tell you when you've reached optimal temperature for charging?

 

[Cmotors]

You shouldn't have to refrain from charging when the battery is cold. This, because Tesla's use thermal management to control how the battery is charged based primarily on current temperature and state of charge (how empty/full the battery is). You can charge the battery when it is cold, and thermal management will determine how fast the battery charges to protect the battery. If really cold, it will trickle charge and the act of charging will slowly warm up the battery. Essentially, it will take a lot longer than normal to charge. Once the battery warms up, speed of charge will increase safely.

In a perfect world, we could provide the ideal Goldilocks treatment to the battery (not too hot, not too cold, but just right). Otherwise, thermal management reduces regenerative braking when the battery starts to get colder than the perfect temperature. The further away from perfect temp range, the more regen is lost, and the slower wall/supercharger charging is. This because both activities charge the battery, and thermal management protects the battery. If possible, you can try to mitigate this with your own activities to protect the battery and make things more practical for your usage, but ultimately, thermal management bears the most weight of this.

 

[pcons]

I didn't know about refraining from charging when the battery is cold. Where did you learn about that? And does it mean one should heat the car before charging? Will the car tell you when you've reached optimal temperature for charging?

You don't have to worry about during charging. The car will do its thing. They were referring to why Regen dots dissapear.

 

[longshot49]

I have seen limited regen in as "warm" as 50 oF this fall.

Charging a cold battery is not a problem, the only issue would be slow charging until the battery warms up.

 

[Funkmobile]

Checking in again after testing with speeds greater than 80kph.

Relevant data:
P3D+
245/40/R19 Pirelli Winter Sottozero 3 on TST 19" Wheels (for PUP)
Cloned TPMS sensors (from OEM 20" wheels)
2018.44.2 Firmware Version

Drove last night at 130kph in stormy rainy weather @ 11 degrees Celsius with full regen bar.

Regen felt normal when driving both manual and on autopilot.

 

[thesteve]

Update, today it's around 1 degrees so not that cold, I'm on 44.2 (and RWD) ... Regen seems close to normal (80-90% normal) even at higher speeds, I've driven maybe 700-1000km since putting on winters so I don't think it's a timing thing, they must have changed something in 44.2, anyway much happier with my one pedal driving it's great!

 

[Tony_YYZ]

Update, today it's around 1 degrees so not that cold, I'm on 44.2 (and RWD) ... Regen seems close to normal (80-90% normal) even at higher speeds, I've driven maybe 700-1000km since putting on winters so I don't think it's a timing thing, they must have changed something in 44.2, anyway much happier with my one pedal driving it's great!

Definitely not the same for me. I still only really feel it kick in at 30km/h or less. Could be a difference between tires though. R3's here.

 

[Flexbomb]

Definitely not the same for me. I still only really feel it kick in at 30km/h or less. Could be a difference between tires though. R3's here.

Same here. Definitely not the same. XI-3 for me. I've noticed myself using much more brake than before. I hope this gets updated for us soon.

 

[Malijai]

Update, today it's around 1 degrees so not that cold, I'm on 44.2 (and RWD) ... Regen seems close to normal (80-90% normal) even at higher speeds, I've driven maybe 700-1000km since putting on winters so I don't think it's a timing thing, they must have changed something in 44.2, anyway much happier with my one pedal driving it's great!

It is the same for me (RWD, Michelin Xice), the regen is back and seems comparable to what I had last month (but it is difficult to compare because of the snow and temperature) but there is a regen now

 

[thesteve]

Same here. Definitely not the same. XI-3 for me. I've noticed myself using much more brake than before. I hope this gets updated for us soon.

I’m on conti’s but all winter tires would be similarly squishy lol

 

[Muskol]

Definitely not the same for me. I still only really feel it kick in at 30km/h or less. Could be a difference between tires though. R3's here.

Same for me on R3's. The only time I've felt the full regen at speeds above 30km/h was last Thursday morning when it was -18 C, presumably the compound firmed up enough.

 

[longshot49]

@Funkmobile I think it's mostly RWD that are having this problem.

AWD seem to be spared.

 

[pcons]

@Funkmobile I think it's mostly RWD that are having this problem.

AWD seem to be spared.

Re posting this since it is a bunch of pages back, but I've done a bunch of quantitative testing showing that this issue is not isolated to RWD only, but for some reason people keep claiming that it is. Not getting mad, just trying to make sure people have the facts. There are people with AWD reporting that there isn't an issue, and there are some who definitely report it. The plots here demonstrate before/after winter tire swap taken getting off the highway at the same exit a few weeks apart. I still dont feel the regen being any better/worse but once I do I will repeat the measurements.

Who has lost regen with winter tires?

 

[bijan]

Re posting this since it is a bunch of pages back, but I've done a bunch of quantitative testing showing that this issue is not isolated to RWD only, but for some reason people keep claiming that it is. Not getting mad, just trying to make sure people have the facts. There are people with AWD reporting that there isn't an issue, and there are some who definitely report it. The plots here demonstrate before/after winter tire swap taken getting off the highway at the same exit a few weeks apart. I still dont feel the regen being any better/worse but once I do I will repeat the measurements.

Who has lost regen with winter tires?

From what I remember there were a bunch of people with rwd that were reporting no regen at 80-100km/h. I think some said one of the updates since then has improved things. Your data with AWD gave 1/2 the regen than all seasons.

There may have been someone with AWD reporting no regen at higher speeds it just seems more common with RWD.

Perhaps it's common with AWD just not as extreme so not immediately noticeable when not measured.

 

[longshot49]

@pcons I typed "mostly"

A few AWD come in this thread an go "I ain't got no probs" and walk out

One pedal driving and being able to adjust to any flow/driving speed was one of my top most favorite thing about the 3. I let go of that for now :/

Just saw your graph on decel - what are you using for that?

 

[pcons]

@pcons I typed "mostly"

A few AWD come in this thread an go "I ain't got no probs" and walk out

One pedal driving and being able to adjust to any flow/driving speed was one of my top most favorite thing about the 3. I let go of that for now :/

Just saw your graph on decel - what are you using for that?

Fair enough on the mostly

I'm in 100% agreement that losing the 1 foot driving is annoying. I've mentioned in other posts how neither the volt or Bolt have this issue of limiting regen at such mild temps. The bolt Regen is actually much better than the 3 IMO because it is stronger AND takes you to a full stop. But that's a different discussion vs losing Regen or it being reduced.

From the graphs the Regen looks to be about half, but you can for sure feel it almost doing nothing so the graphs are a bit deceiving. That's why I'd be interested in seeing similar data on a RWD to see how it matches up.

I plan on comparing low and standard Regen as well because tonight I was playing with it being on and off and at high speeds I didn't notice any difference between low and standard Regen. When in low there is no extra kick at around 30 km/h, but that's about the only difference I felt. But this does need more testing.

Doing the measurements is dead easy. It's accelerometer data from my cell phone. There are a bunch of apps that will log that into a CSV file, then I put it in excel and plot a running average trend line to take out some of the noise. It's important to have the phone flat relative to gravity so that you measure a true y axis deceleration and don't get skewed by an angle. The app I used is physics toolbox on the play store and I have a pixel 2 xl, but any smartphone should work fine.