One pedal mode uses the brakes?

[BlueWRXPride]

So far I am loving the one pedal driving mode that is now available. But this weekend I noticed something interesting. My car had been outside all night in the cold, and when I got in to drive there was literally no regen since the battery was all cold. So driving along at normal speeds would result in coasting, as expected. However I found that if I was coasting below 7mph or so, the car would still slow to a stop.

Since the battery is too cold for regen, I assume that this slowing to a stop is being done with the brakes. I just found it interesting and a little unexpected.

 

[derotam]

So far I am loving the one pedal driving mode that is now available. But this weekend I noticed something interesting. My car had been outside all night in the cold, and when I got in to drive there was literally no regen since the battery was all cold. So driving along at normal speeds would result in coasting, as expected. However I found that if I was coasting below 7mph or so, the car would still slow to a stop.

Since the battery is too cold for regen, I assume that this slowing to a stop is being done with the brakes. I just found it interesting and a little unexpected.

I am going to guess here, that at that low of a speed, the regen potential in not enough to damage the battery. Remember, at 240V 32A, that is 7.6kW... With no regen, I know for a fact that my car will still put the full 7.6kW into the car for charging. At low speeds, regen isn't going to be much more than that.

Edit...found my data... Ok given that the max AC charge rate is 11.5kW(240v 48A), even with full regen available, at ~8.5mph is where it crosses below 11.5kW regen. So it makes sense for regen to be available at low speeds.

 

[Johnny Mac]

Yes it uses the brakes

 

[derotam]

Yes it uses the brakes

After it gets to 0mph yes, but from say 10mph...no.

 

[Johnny Mac]

After it gets to 0mph yes, but from say 10mph...no.

That is incorrect. It uses the brakes at approximately 7 miles an hour

 

[WilliamG]

So far I am loving the one pedal driving mode that is now available. But this weekend I noticed something interesting. My car had been outside all night in the cold, and when I got in to drive there was literally no regen since the battery was all cold. So driving along at normal speeds would result in coasting, as expected. However I found that if I was coasting below 7mph or so, the car would still slow to a stop.

Since the battery is too cold for regen, I assume that this slowing to a stop is being done with the brakes. I just found it interesting and a little unexpected.

The motor is electronically slowing you down. It’s just not regenerating any energy. In fact, I have zero doubt that Tesla could modify how the car works at any speed, even if the car is freezing cold and has no regen, to give the impression of full regen when driving. They won’t, though, because it uses battery power to do so.

 

[NOLADriver]

I wondered the same thing and thought this scenario. I was very used to the regen stopping and knew how to modulate the pedal to rarely ever touch the brakes until the last stopping point. This would save all wear and tear on the brakes and make them last well over the projected 100k mark. But now with the hold function the car is constantly applying regen and brakes. Do I really need the hold function if its using brakes more than I would using just good pedal modulation and very very little actual brakes. I was fine with it before hold came out and wanted to keep my brake use to a min.

 

[WilliamG]

That is incorrect. It uses the brakes at approximately 7 miles an hour

The friction brakes are not used at any point in the braking process until the car hits 0mph.

 

[Johnny Mac]

The friction brakes are not used at any point in the braking process until the car hits 0mph.

you go stick your foot behind the brake pedal using one pedal driving on the accelerator pedal and you tell me if you don’t feel the pressure before hitting zero. You will feel it the brake pedal pushers itself down long before you hit zero

 

[WilliamG]

you go stick your foot behind the brake pedal using one pedal driving on the accelerator pedal and you tell me if you don’t feel the pressure before hitting zero. You will feel it the brake pedal pushers itself down long before you hit zero

I will test that further. Up till this point I haven’t felt anything, but definitely feel it when it comes to a complete stop (and the click sound).

It doesn’t make sense to me that it would, as I tested on a steep decline and it still didn’t appear to use the friction brakes but instead the motor as brakes (can see the regen bar switch to energy usage) to slow the car down to 0. Unless it’s blending the motor and friction brakes. But my impression is that it’s not.

Either way I’ll test some more.

 

[RSL2020]

you go stick your foot behind the brake pedal using one pedal driving on the accelerator pedal and you tell me if you don’t feel the pressure before hitting zero. You will feel it the brake pedal pushers itself down long before you hit zero

Well that's disappointing... I can modulate brakes for stopping better than a computer. I am beginning to think I want the old mode back.

 

[Big Earl]

Well that's disappointing... I can modulate brakes for stopping better than a computer. I am beginning to think I want the old mode back.

The “old mode” is still there - labeled as ROLL, which I prefer.

 

[derotam]

That is incorrect. It uses the brakes at approximately 7 miles an hour

I'm open...because I haven't tested it yet...how do you know?

 

[NOLADriver]

@RSL2020

Just go in your menu and select it.

 

[ALSETJC]

Can somebody try coming to a stop run out of the car and lick the discs to see if they are warm ?

 

[derotam]

So far I am loving the one pedal driving mode that is now available. But this weekend I noticed something interesting. My car had been outside all night in the cold, and when I got in to drive there was literally no regen since the battery was all cold. So driving along at normal speeds would result in coasting, as expected. However I found that if I was coasting below 7mph or so, the car would still slow to a stop.

Since the battery is too cold for regen, I assume that this slowing to a stop is being done with the brakes. I just found it interesting and a little unexpected.

Need a data point...how cold was it where your car was? If in a garage, how cold was it in the garage. Also, when you say "literally no regen", can you be moer specific in terms of what the regen bar looked like, how many dots, how much solid....whatever you can would help.

 

[jsmay311]

So far I am loving the one pedal driving mode that is now available. But this weekend I noticed something interesting. My car had been outside all night in the cold, and when I got in to drive there was literally no regen since the battery was all cold. So driving along at normal speeds would result in coasting, as expected. However I found that if I was coasting below 7mph or so, the car would still slow to a stop.

Since the battery is too cold for regen, I assume that this slowing to a stop is being done with the brakes. I just found it interesting and a little unexpected.

When a small (non-zero) amount of regen is available, as is often the case with a cold battery, it's much more noticeable at low speeds than it is at higher speeds due to the basic physics at work.

And if you're using power to heat the cabin, any small amount of regen that you might otherwise see reflected in the power meter on the screen with a tiny green bar might be offset by the positive power consumption by the cabin heater, thus making it look like there's zero regen since the power meter shows no net power flow.

It uses the brakes at approximately 7 miles an hour

That doesn't gel with my experience so far. I notice an audible engagement of the friction brakes only at 0mph. It's quite clear/noticeable.

And I'm guessing it hasn't gotten so cold in Alabama to lose ALL regen, no?

you go stick your foot behind the brake pedal using one pedal driving on the accelerator pedal and you tell me if you don’t feel the pressure before hitting zero. You will feel it the brake pedal pushers itself down long before you hit zero

I've never noticed the brake pedal moving on its own in my Model 3, even in AP/TACC when it's definitely braking. Is this really a thing?
(Edit: others have correctly pointed out that this IS a thing that I’ve just not noticed before. My bad.)

 

[Big Earl]

I've never noticed the brake pedal moving on its own in my Model 3, even in AP/TACC when it's definitely braking. Is this really a thing?

Yes - the brake pedal moves every time the car applies the brakes. The brakes are applied via the electromechanical brake booster, which is physically connected to the pedal.

 

[Don_Joe]

you go stick your foot behind the brake pedal using one pedal driving on the accelerator pedal and you tell me if you don’t feel the pressure before hitting zero. You will feel it the brake pedal pushers itself down long before you hit zero

Even if that is the case and the brake pedal does move down when you get below 7mph that doesn't mean for certain that it is using the friction brakes. However, I agree that it is using friction brakes because at low speeds the model 3 motors probably can't generate enough braking torque to come to a complete stop. So there is most likely friction braking going on which may or may not be reflected in the physical brake pedal moving.

 

[DJVoorhees]

Well that's disappointing... I can modulate brakes for stopping better than a computer. I am beginning to think I want the old mode back.

Yeah. I changed back to roll pretty quickly.