Regenerative braking vs brake pedal

[Tech5150]

There is a road outside of Yosemite National Park called Old Priest Grade that I've read to be 18-20% grade in parts. I've lost brakes in older cars coming down it. In my '05 Prius, I would lose regen part way down as the battery became fully charged. I've recently taken my M3P+ down it and could control the speed to down to a CRAWL if I wanted using only accelerator pedal. No brake pedal at all. Surreal...I only had to use brakes in the last 15' coming to the stop sign. Is this really ONLY regen? So, it doesn't use friction brakes at all on aggressive decel? Very hard for me to get my mind around slowing a 4100lb vehicle to 15mph coming down a cliff...I did not smell any brakes at any point. I was beside myself as we came down it, bugging my wife because I was like a little kid. "DO YOU REALIZE WHAT'S HAPPENING RIGHT NOW??? I'M NOT USING ANY BRAKE AT ALL!!!" I was blown away... So, really? It doesn't use brakes at all during regen? Love this car...

 

[Ciaopec]

There is a road outside of Yosemite National Park called Old Priest Grade that I've read to be 18-20% grade in parts. I've lost brakes in older cars coming down it. In my '05 Prius, I would lose regen part way down as the battery became fully charged. I've recently taken my M3P+ down it and could control the speed to down to a CRAWL if I wanted using only accelerator pedal. No brake pedal at all. Surreal...I only had to use brakes in the last 15' coming to the stop sign. Is this really ONLY regen? So, it doesn't use friction brakes at all on aggressive decel? Very hard for me to get my mind around slowing a 4100lb vehicle to 15mph coming down a cliff...I did not smell any brakes at any point. I was beside myself as we came down it, bugging my wife because I was like a little kid. "DO YOU REALIZE WHAT'S HAPPENING RIGHT NOW??? I'M NOT USING ANY BRAKE AT ALL!!!" I was blown away... So, really? It doesn't use brakes at all during regen? Love this car...

No, it does not.

 

[Tech5150]

No, it does not.

Mad science...

 

[chasharris]

The reduction in regen under hard braking has nothing to do with the application of friction brakes.
It is the regen reduction you would see anyway as speed is reduced.

Is it actually possible to see the regen you're getting? Is it displayed anywhere?

 

[dark cloud]

There is a road outside of Yosemite National Park called Old Priest Grade that I've read to be 18-20% grade in parts. I've lost brakes in older cars coming down it. In my '05 Prius, I would lose regen part way down as the battery became fully charged. I've recently taken my M3P+ down it and could control the speed to down to a CRAWL if I wanted using only accelerator pedal. No brake pedal at all. Surreal...I only had to use brakes in the last 15' coming to the stop sign. Is this really ONLY regen? So, it doesn't use friction brakes at all on aggressive decel? Very hard for me to get my mind around slowing a 4100lb vehicle to 15mph coming down a cliff...I did not smell any brakes at any point. I was beside myself as we came down it, bugging my wife because I was like a little kid. "DO YOU REALIZE WHAT'S HAPPENING RIGHT NOW??? I'M NOT USING ANY BRAKE AT ALL!!!" I was blown away... So, really? It doesn't use brakes at all during regen? Love this car...

going off the top of my head I believe regen can charge the battery at a max rate of about 75 kW.

 

[serendipitous]

Is it actually possible to see the regen you're getting? Is it displayed anywhere?

Since this is in the Model S forum - yes, on the energy gauge that's in the right instrument cluster screen by default. When it goes green and to the lower right side, it's showing you your regen in kW. I think I've heard the Model 3 has a line somewhere on the left side of its screen that shows the same info.

 

[chasharris]

Since this is in the Model S forum - yes, on the energy gauge that's in the right instrument cluster screen by default. When it goes green and to the lower right side, it's showing you your regen in kW. I think I've heard the Model 3 has a line somewhere on the left side of its screen that shows the same info.

Thanks - great. I'll check it, next time on my M3 I'm allowed out...

 

[chasharris]

Thanks - great. I'll check it, next time on my M3 I'm allowed out...

...on my M3, next time I'm allowed out...

 

[serendipitous]

Thanks - great. I'll check it, next time on my M3 I'm allowed out...

Looks like it's here on the 3. To the left/green ==> Regen, to the right and probably orange would be usage. If regen is limited due to cold/full battery/etc you should see dashed lines on the left.

 

[TyPope]

There is a road outside of Yosemite National Park called Old Priest Grade that I've read to be 18-20% grade in parts. I've lost brakes in older cars coming down it. In my '05 Prius, I would lose regen part way down as the battery became fully charged. I've recently taken my M3P+ down it and could control the speed to down to a CRAWL if I wanted using only accelerator pedal. No brake pedal at all. Surreal...I only had to use brakes in the last 15' coming to the stop sign. Is this really ONLY regen? So, it doesn't use friction brakes at all on aggressive decel? Very hard for me to get my mind around slowing a 4100lb vehicle to 15mph coming down a cliff...I did not smell any brakes at any point. I was beside myself as we came down it, bugging my wife because I was like a little kid. "DO YOU REALIZE WHAT'S HAPPENING RIGHT NOW??? I'M NOT USING ANY BRAKE AT ALL!!!" I was blown away... So, really? It doesn't use brakes at all during regen? Love this car...

I rode all the way down Pike's Peak without using my brakes. I maintained a slow speed and never once had to put a foot on the brakes till the very end to stop for the guy with the thermometer to check my brakes to see if I could keep going. There were several sedans that he made pull over till their brakes cooled but when he pointed the thing at my brakes, he looked at it, looked at me, aimed it at the brakes again, looked at it, shook his head in disbelief, looked at me and waved me on. I shifted out of 4X4 Low and drove away. Those people in the sedans were staring daggers at me and probably wondering how that F-350 Crewcab Longbed pickup managed THAT trick. It's all in the gearing, baby... all in the gearing... Well, that and 6.4L of diesel engine.

 

[chasharris]

View attachment 537544
Looks like it's here on the 3. To the left/green ==> Regen, to the right and probably orange would be usage. If regen is limited due to cold/full battery/etc you should see dashed lines on the left.

Thanks - I never spotted that line (still new to the M3)

 

[Watts_Up]

I rode all the way down Pike's Peak without using my brakes. I maintained a slow speed and never once had to put a foot on the brakes till the very end to stop for the guy with the thermometer to check my brakes to see if I could keep going. There were several sedans that he made pull over till their brakes cooled but when he pointed the thing at my brakes, he looked at it, looked at me, aimed it at the brakes again, looked at it, shook his head in disbelief, looked at me and waved me on. I shifted out of 4X4 Low and drove away. Those people in the sedans were staring daggers at me and probably wondering how that F-350 Crewcab Longbed pickup managed THAT trick. It's all in the gearing, baby... all in the gearing... Well, that and 6.4L of diesel engine.

This is what all the trucks do to avoid running brake failure.

They drive down at the same speed that when going up.

 

[smartypnz]

Yes, the 3 shows it - but really hard to see and if you watch too long - you drive off a cliff (which I think will drop the regen to zero).

 

[Magiken]

Out of curiosity, has anyone replaced their brake pads yet? I'm on 70K miles and nowhere near ready.
Gives my tire/brake guy a chuckle when I ask how the pads look.

 

[Ciaopec]

Out of curiosity, has anyone replaced their brake pads yet? I'm on 70K miles and nowhere near ready.
Gives my tire/brake guy a chuckle when I ask how the pads look.

I am at 126,000 miles and nowhere near ready. I am a big regen fan and avoid brakes whenever feasible.
Which, I guess for me, is almost always.

 

[Exscite]

I love the regen braking and I hardly touch the brake pedal at all. I live on the hills above Los Angeles and enjoy it every time going downhill.
I have noticed an intriguing behavior (of my model 3, with no autopilot) :
Approaching a stop sign with white line across the road, I leave the accelerator and let the regen do the braking. Most often then not, the car "knows" to stop precisely in front of the line, regardless my approach speed, or the inclination of the road (within reason of course). I've experienced it many, many times. Once at the white line, it "locks" the brakes".

That's fun.

I wonder, is it possible that the Tesla's visual system (cameras) help in controlling this precision braking?

 

[Bad Dolphin]

On the Model 3, the regen line is green when regenerating power and black in the opposite direction when consuming power. At night, the color changes when the display background auto changes to black.

Awesome vehicles.

 

[Bad Dolphin]

I love the regen braking and I hardly touch the brake pedal at all. I live on the hills above Los Angeles and enjoy it every time going downhill.
I have noticed an intriguing behavior (of my model 3, with no autopilot) :
Approaching a stop sign with white line across the road, I leave the accelerator and let the regen do the braking. Most often then not, the car "knows" to stop precisely in front of the line, regardless my approach speed, or the inclination of the road (within reason of course). I've experienced it many, many times. Once at the white line, it "locks" the brakes".

That's fun.

I wonder, is it possible that the Tesla's visual system (cameras) help in controlling this precision braking?

We’ve noticed this too.

Both of us just LOVE the one pedal driving. As I explained to my wife when we made the switch from ICE muscle cars that she loved to drive in lower gears for both the power and deceleration capability, it’s liking being in first gear all the time!

 

[Magiken]

Agreed on all of the above. I find it amusing that occasionally people will complain about the feel of the regen. I actually get slightly annoyed when I have to push the brake. It's become a challenge to see if I can make one set of pads last forever. I find myself often debating if I should turn off 'creep' to get even just a little more regen when slowing.

 

[smartypnz]

Agreed on all of the above. I find it amusing that occasionally people will complain about the feel of the regen. I actually get slightly annoyed when I have to push the brake. It's become a challenge to see if I can make one set of pads last forever. I find myself often debating if I should turn off 'creep' to get even just a little more regen when slowing.

My wife's first Model S (2013) went around 185,000 before trading in.

But her last service check revealed the brake pads had used less than 1 m/m. We were told a million miles would have been achievable.