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Why not regen on pressing the brake pedal?

Why not regen on pressing the brake pedal?

One thing that surprised me when taking a Tesla test drive was that the regeneration kicked in when I took my foot off the accelerator rather than when I pressed the brake pedal lightly. My (naïve) expectation was that taking your foot off the accelerator would let you coast and the 1st 1/4 or so of the brake pedal travel would engage the regeneration and pressing further would add in the conventional brakes.

Given the number of threads on coasting techniques, this would seem to be an easier way to drive than finding the sweet spot on the throttle that allows you to coast (or putting the car into neutral). I'd also be more comfortable when coasting up to a light if my foot was already on the brake so that I just need to apply pressure if I end up closing too quickly.

Does anyone have any theories on why things were not set up this way? The obvious one is that Tesla wanted a direct mechanical linkage from pedal to brakes rather than something more complex.

jbunn | 4 novembre 2013

When you take your foot off the "go" pedal, regen is already on full.

There is nothing more to be gained via the brake pedal.

nickjhowe | 4 novembre 2013

The driving experience is MUCH better using the throttle for regen. In addition to enabling 'one foot driving', it is very difficult to get a smooth transition between motor regen and physical brake application when they are both controlled through the same pedal. KISS

TeslaLandShark | 4 novembre 2013

It felt really weird to me when I did my test drive last December. I thought I would set regen on low when I got my MS. However after I picked up the car in March, just driving it for one day I was already really enjoying the one pedal driving. I liken it to down shifing to slow down a car with a manual transmission except a lot easier!

ModelS3P | 4 novembre 2013

After driving it for a day or two, you realized how much better Tesla's implementation is. In normal city driving, you are not constantly switching back and forth between accelerator and brake; it's basically one-pedal driving for the most part. At constant speed, you can either find the sweet-spot (just like every other vehicle) or use cruise control which seems to be pretty energy efficient to me. You do control the speed of deceleration by feathering the accelerator instead of feathering the brake, but either way you would be feathering a pedal, and I would rather feather the pedal that my foot is already on.

This article (http://everydaydriver.com/exotic/tesla-model-s-review/), which is one of the more well-balanced reviews, also mentions the braking system:
"Of course all this power and weight requires good braking and Tesla pioneers again by placing the regenerative feature on the accelerator pedal instead of the brake. Lifting off the go pedal begins the regenerative cycle and even illuminates the brake lights to alert other drivers. As a result the brake pedal feels like any other well-tuned automobile instead of the difficult to modulate fight so often associated with regenerative brakes."

mcx-sea | 4 novembre 2013

When you step on the brake pedal, you are pushing the brake pads against the brake discs. This friction slows the wheel, but it also produces heat which is wasted energy. It also removes a microscopic layer from the brake pads, requiring eventual replacement.

Using regen instantly converts your electric motor into an electric generator. This generator converts the energy used to slow the car into electricity, which is pumped back into your battery thus adding range.

Use your brakes for emergency stops, to slow or stop "creep" and to hold the car in place while stopped on a slope. Brake pads won't wear if the car is not moving, thus brake pads should last virtually forever.

Captain_Zap | 4 novembre 2013

What I love most about the Model S(aside from the acceleration's instantaneous response) is the fact that it didn't coast and regen made for greater control of the car. I can take my foot off the accelerator and the car responds immediately just as it should.

I always hated it when I took my foot off the gas and the car just kept going as if it had a mind of its own. I guess it sells a lot of brakes.

kamingcheng | 4 novembre 2013

I was initially very concerned that I could not coast in the Model S. Coasting, I naively thought, was like free mileage.

Now one of my favorite features is regenerative braking.

I still need to drive an ICE on some days. Now I think it is such an awkward car design to burn gas to accelerate, only to burn brake pads and waste the energy to decelerate. After getting used to the Model S, I feel like driving a boat whenever I am coasting in an ICE.

jchangyy | 4 novembre 2013

I also agree. this is much better than my previous car (Camry hybrid--hitting the breaks kicked in regen).

GaryREM.va.us | 4 novembre 2013

Absolutely love the way Tesla has this set up.

Got the car Saturday and within a very short period of time it just felt right. Had never driven any other hybrid, so had no preconceived notions.

Car t man | 4 novembre 2013

Still, this should be offered as a choice in the menu. It is easy to implement. The controller has this option and the choice should be
available to the driver. There is no need to take this option away.

TeslaTap.com | 4 novembre 2013

@Car t man - I think most of us would disagree. The traditional hybrid systems that integrate regen and the brake pedal are far more complex and never very clean (i.e. the transition from regen to physical brakes is clunky at best).

I can't see any reason for Tesla to waste a huge amount of time trying to duplicate the crappy system used by other manufacturers. It is far from easy to implement either.

I expect you'll see everyone copying Tesla in the next few years.

Devin B | 4 novembre 2013

I had a 2011 Leaf for two years before I got my Model S. The Leaf required using the brake pedal to achieve full regen. The way the Model S works is far superior. I drive 90% of the time with only one pedal instead of two, and it is much easier to get full regen and not use the brakes at all!

I love it the way it is!

Bighorn | 4 novembre 2013

We have a 2007 Prius with about 170,000 miles on it, and I still haven't figured out the regen. Model S was intuitive from day 1.

DTsea | 4 novembre 2013

car t man your option would require sensor integration on brake pedal and control reengineering. i would not want that complexity added to my car.

Chuck Lusin | 4 novembre 2013

The second that the brake pads touch the rotors, you instantly cut into your potential regen. This is the reason it is not on the brake.

When you coast in the S, you have a net energy usage of zero. So just find the correct pressure on the GO pedal.

Epley | 4 novembre 2013

Nickhowe and Captain Zap have it correct!

I LOVE the regen on the accelerator pedal, and I will never go back to a car that coasts if I can help it! Coasting feels so out of control now that I'm used to more refined driving.

carlk | 4 novembre 2013

People Car t man was only suggesting it to be offered as an option. What's the reason it should not be one when there is the low regen option?

Chuck Lusin | 4 novembre 2013

Guessing, I would want the brake pedal, to have an instant response all the time.

Second, the brake system works just the same an ICE car.

I would think that this is true: "The obvious one is that Tesla wanted a direct mechanical linkage from pedal to brakes rather than something more complex."

DallasTxModelS | 4 novembre 2013

@Carlk

Because the brakes are mechanically controlled by the pedal. Regen is the motor being pulled by the motion of the car. With software you can change the feel of more or less regen and the appearance of "coasting" and "creep" but both are wasting energy. There is not a true "coast" only the feel of coasting. The motor is directly connected to the axle. There is not a clutch that frees the axle from the motor.

TeslaLandShark | 4 novembre 2013

Is there anyone who actually owns the car who does not like the way the regen currently works? The person who posted this just took a test drive. I felt the same way after my test drive as it was very different than what I was used to. There's already a way to set regen to low. There are a lot of other feature requests that the majority of owners would want instead of a regen "off" option. Like beam me my 5.6 so I can stake that vampire once and for all!

jcaspar1 | 4 novembre 2013

I have had my Tesla for 2 days and the regen is very natural. Just like driving my 1997 Dodge Viper where the 8 liter motor slows the car significantly when you let off the throttle only now I get the energy back!
P.S. Have 5.6 with sleep. Left the car with 125 miles at 8pm last night and left with 125 this morning at 7am!

jcaspar1 | 4 novembre 2013

I have had my Tesla for 2 days and the regen is very natural. Just like driving my 1997 Dodge Viper where the 8 liter motor slows the car significantly when you let off the throttle only now I get the energy back!
P.S. Have 5.6 with sleep. Left the car with 125 miles at 8pm last night and left with 125 this morning at 7am!

Roamer@AZ USA | 4 novembre 2013

You will love how regen works from the accelerator once you drive the car for a few hours. It is an amazing system.

I only use the brakes when I want to come to a complete stop. My Nissan Leafs were set up how you describe so I have done it both ways. The Tesla system is much better. With the leaf I had to constantly look at the regen gauge to make sure I did not over brake and waste the regen. With the Tesla you know exactly when you are regenerating and when you are heating up the brakes to waste energy.

Once you get the feel of how it works you will never go back.

Thomas N. | 4 novembre 2013

Drove only the Model S for a month and then had to drive our ICE because my wife had the Tesla. I immediately expected the heavy regenerative breaking I was used to in the Tesla and almost slammed into a car in front of me. I absolutely HATED the coasting in the ICE. It felt so wrong. I rode the brakes (road the breaks for Brian H's amusement) so much that I thought I must be doing something wrong.

Trust me on this - Tesla got it correct. It's awesome.

Brian H | 5 novembre 2013

Pretty consistent: people anticipate they won't like one-pedal driving, but do. The only hang-up so far seems to be those who back off too much on the goose pedal while driving, and constantly activate the brake lights for a second or two. Drivers behind get nervous; what if you are actually braking, hard, for some emergency?

I think a more informative taillight signaling system is warranted.

Car t man | 5 novembre 2013

@TeslaTap

the one pedal thing isn't Tesla's per se. It has been used in EVs and especially conversions for a very long time. Each normal controller has
settings through which the user then adjusts practically everything.
AC inverters are very cool that way. So you can set whether you want
braking on accelerator pedal, brake pedal, both, at which starting point
in terms of depression of the pedal, how the speed of lifting affects it,
etc. Tesla has this also but not for the end user. It is easy for them.

It can be made into two or three profiles, users can switch between. You
will get used to any one of these that Tesla throws at you by default but
some users, especially advanced, also those going to track, etc.. will
want to be able to alter these settings. The point is that everything
is there and should be available. Either by default somewhere in the menu,
or at SC, if you ask for it. Maybe an advanced menu or something.

The point is that if one needs to ask, one likely has a reason for it.
Tesla made a single, sound and nice choice. But it made it for all
users and in an EV, which by default offers multitudes of such settings
by design. Again, many see any proposal as an attack or some kind of
a dismissal of Tesla's credibility. Keep calm. I am certain Tesla is
already contemplating this. Maybe in a special package or smth.

Different drivers, different skill sets, needs and habits and also past
experience. Even setting the midpoint band in which the car coasts, is
already a plus. But again, this is already in the inverter. Just not
available to the end user currently.

And on brake pedals, the setting would be to use regen on the first 20 or 30% of pedal travel (before pads touch disks) and then from that point on the pads kick in additionally and progressively as they do.

Skotty | 5 novembre 2013

A lot of fans really defend the way Tesla set it up. But I believe it is more natural and a better driving experience if regen (or any braking action) be engaged only when pressing on the brake pedal. The big manufacturers do it this way by default. The problem is, it's a far more complex system than what Tesla is using (with the exception of deciding on when to turn on the brake lights). Is it technically a far cleaner solution to do all regen with the gas pedal and leave the brake pedal to operate the same as on a gas car.

I think Tesla's direction on this is reasonable and acceptable.

Skotty | 5 novembre 2013

Additional note: As I understand it, you can reduce the regen attached to the gas pedal to it coasts more like a typical car, but then you lose the regen. This is one of the respects in which the Volt is superior to the Model S; the Volt can be set to "L" to regen when letting off the gas for the one-pedal fans, and can also be set to "D" where it coasts, but in "D" it doesn't lose any regen.

Kimscar | 5 novembre 2013

In the real world for the majority of driving coasting doesn't buy you anything. Example if you live in a city where there is traffic or in hilly areas or mountains. On the open road no need to coast just cruise.
And as pointed out the brake pads are saved in this process.

cmaso | 5 novembre 2013

@Tkela - I am generally a one pedal driver these days, however I have often thought the same thing. Usually it's when I'm readjusting my foot on the accelerator pedal and regen kicks in hard…

To all those, like me, who believe Tesla can do no wrong. Tkela is a customer, and she is stating that she would like something different than what is begin offered. The great thing about Tesla is that they listen to their customers. If there is a mechanical/technical reason why an integrated regen/breaking pedal wouldn’t be valuable, then I guess we won’t see one. But if it is possible (financially/technically, etc), then I for one think it should be an option… just like creep…

Note: I drive home in bumper to bumper traffic that fluctuates between 0 and 70 mph often, and I only use my break under 10 mph (so I love one pedal driving). I’m just saying that the more Tesla can deliver solutions to all their customers, the more cars they will sell, the better for all!!!

Car t man | 5 novembre 2013

@Skotty
changing those settings in the controller is nothing but a few clicks.
To chose functions of pedals, etc. Just like you can set regen
level in the menu. Those would simply be additional options like
that one.

@Kim
actually, in daily driving, for majority of users, when monitoring
traffic, coasting is a very notable factor in efficiency. One does
not find themselves only in situations when they cannot use it.
Often they can and should. Regen is only for when one would
need to use brakes. It is still far better to
1. Coast when possible and applicable
2. Regen
3. Brake

In that order. Regen means energy transformation. It means additional
losses but is still much much better than regular braking.

The point is, you should not be taken away the choice to chose any
if not needed and that the way you engage which could easily be left
to the user. Anything else is discussing preferences and habits, which i itself is no more a constructive debate than say debating party politics
or if any religion is better than others. Because it is all already built into the car, just not yet accessible, the user could be left with a choice.

DTsea | 5 novembre 2013

@skotty, No I think Tesla has it right. Why should you keep moving your foot? How many accidents caused by people pressing the wrong pedal?

Roamer@AZ USA | 5 novembre 2013

Someday there will be apps that let you change all kinds of settings and display info anyway you want. Lots of space on that app screen.

Having driven brake pedal regen EV's and Tesla accelerator regen I much prefer the Tesla system.

The way Tesla does it you always know when you are regen slowing and when you are brake slowing. Just takes reprogramming your brain to not jerk your foot off the accelerator. Takes about 100 miles and your brain adapts to the system.

Probably already a study out that shows the improvement in stopping distance and time since slowing starts before you ever get your foot to the brake pedal. Much safer for panic stops.

NKYTA | 5 novembre 2013

It seems clear that the majority of folks like one-pedal driving with the regen as is (including me). While I grant that not all people like it as such and the OP is allowed to have his/her opinion - I really don't want all the great suggestions for future improvement to lag behind this request.

Go over to the Prioritized Software Enhancement list and cast your vote. My guess is this will be far down the list...

Grin! :-)

Car t man | 5 novembre 2013

@Nkyta

this isn't something that takes one tech's afternoon. They already
have all the settings from testing and saved as profiles, I am sure.
It isn't something that really needs much effort. Or as I said, they
could enable a special firmware with such mods for those who apply.

You could also sign a waver of some kind with that firmware, that
you accept that you will be using the pedals differently and
any damage you cause because of that specific change,..

Having a foot on a pedal constantly also gets tiresome on long drives.
Or they could set it so that when releasing slowly, it regens, and
when quickly, it coasts. Modern inverters have this built in also.

A modern EV, especially in this price range, is just to good to
be left completely spartan in terms of settings, just because
mainstream users don't find them useful or don't know they exist
and can be useful. The babysitting nature of Apple repels
many users. Myself included. When not dangerous, I think
they should oblige, since it is already built into the car.

To someone who knows EVs it is much like you having your seat's
travel artificially shortened by 15%, if you happen to be tall.
It can bug you.

mrspaghetti | 5 novembre 2013

@Car t man

I am not so sure you are correct that moving regen from the right pedal to the left one would be a mere software change. It is my understanding that the brakes are a simple mechanical system that is physically completely separate from the motor/inverter, and thus from the regen system. If that is the case it would be a significant effort to make the change, and considering that it seems to be (at least, according to the responses on this thread) low demand, not worth it.

+1 to all who said the Tesla mode of regen is better than what's being suggested by the OP. Once you drive the car for a bit, you'll never go back.

mrspaghetti | 5 novembre 2013

@Car t man

Having a foot on a pedal constantly also gets tiresome on long drives

Isn't that what cruise control is for?

ModelS3P | 5 novembre 2013

@Car t man

Having a foot on a pedal constantly also gets tiresome on long drives

No different from an ICE on long drives.

GaryREM.va.us | 5 novembre 2013

@mrspaghetti +1

Unless there are position sensors on the brake pedal, this will not be a simple 'click' on some magic configurator.

I always worry about these long winded answers when I see the basic premise may be flawed. Maybe our brakes are 'fly by wire'; that would be interesting.

carlk | 5 novembre 2013

Brakes are not fly by wire yet. Eventually they will be, many auto companies are working on that. But we are not talking about brake by wire here. All you need to do is to add a linear potentiometer and feed the signal to the processor.

Car t man | 5 novembre 2013

Gentlemen, brakes have the sensor because the car and controller need to know when the brake is on. For many, this is the first EV and most of you still don't know the usual setting of EVs. All of what I am talking about is already in the car. This is a default set of sensors and settings on any normal EV. DIY cars have this available to end users, if they have the tools and with large and more serious manufacturers, that is available to the technicians. It is already there. Just like creep. It is merely a software command. It is either on or off, the speed/torque of creep, etc. These are all simple settings, changed with clicks on keyboard.

There are long stretches of road one can't drive with cruise on (especially without radar assist) which are annoying and the very fact that ICEs are bound to that, whereas an EV does not need to be, is the point. Why sacrifice such advantages? Trust me, on the Tesla, these settings and what is needed are
already all there. They are just not shown on your menu. It is just
above your access level. Rightfully so. If you don't know they are
there, you should not meddle with them. If you know and understand
them, you should be allowed access or be able to ask the technician
to set some things for you.

They are currently at a certain "sweet spot". For Tesla and the vector
that goes through the average of all users. That isn't always optimal
for the most and least savvy users and drivers.

Most of you should not wish the access since more choices might only complicate your user experience. You shouldn't however be against
making those choices available to those who understand and want them.

When you buy a smart phone, you can leave it without any non bundled
software. Many users do that. Many however enrich their experience
with deeper possibilities all the software, etc. offer.

Car t man | 5 novembre 2013

OK: Examples
1. For advanced users, turning traction completely off for instance, for the track is one such setting. This is an example so no need to point out that
the car isn't meant for it. Say for filming a movie action scene..

2. Valet mode. This is for non savvy users or users you don't want to
have full power on. Or loaner speed limitations, etc.

These are all simple clicks on keyboard. ALL of the settings are fully
available via neat hand held tools or PCs to technicians.

AmpedRealtor | 5 novembre 2013

You have far more control if you can slow the car using a single pedal. I find this way of driving to be far superior to the traditional way. You have to learn something new, but it's worth it.

Steinwand | 5 novembre 2013

I recently drove my MS through a pass in the Rocky Mountains with lots of curves. The regen is great in city driving but twice as useful in this senario. The driving experience was amazing how the car would slow for me as needed at every curve and hill without touching my brakes. Try doing that in an ICE.
It kind of reminds me of when I was a kid and had an electric race car set. (You know the one with the black snap together tracks) All I would do is release the accelerator trigger to make the car slow for corners.

NKYTA | 5 novembre 2013

@Car t man
"It isn't something that really needs much effort"

Well, neither is changing the default setting on the Energy App to "Average" which is something I really want - but it isn't super high on the priority list.

Car t man | 5 novembre 2013

It should be. Hopefully Tesla is reading this and making a list.

Captain_Zap | 5 novembre 2013

Changing how regen works would probably end up with the car having to get EPA rated all over again.

Brian H | 5 novembre 2013

Regen should never "come on hard", maybe unless you suddenly come off the pedal.

Mark E | 6 novembre 2013

After driving a Roadster for a weekend and driving a manual ICE normally I'd never want them to have the Tesla regen on the brake rather than the accelerator. It is extremely natural and feels like driving a proper car. I hate automatics and the vague feeling that the automatic transmission gives.

Long drives tiring? Use cruise control.

Regen on the brake pedal - no, it will completely wreck the modulation feel.

EVs should be fun to drive - drive the car for a while before making judgement, the one pedal control is fantastic.

Car t man | 6 novembre 2013

Mark

The point is that you can have one, the other, both simultaneously, etc.
That there is no need to keep the choice about that away from those
users who want the choice. I have been driving EVs for a very long
time so I have more experience than most here and I am trying to
share. That there is even more to be had from the Tesla.

You need to understand that for most, Tesla is the first EV. Not
for everyone. Some have more experience and have tried all options
on many or single vehicles. And like those options.

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