Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Regen braking - full stop

beatle

Active Member
Aug 31, 2019
1,268
724
Springfield, VA
When driving my friend's model 3, I notice that his regen braking will bring him to a full stop which allows for easy one pedal driving in most cases. My S trails off regen around 6 mph to the point that the car will free wheel (for a considerable distance on level ground). I always have to switch to the traditional brakes to come to a full stop in traffic.

Creep is off and regen braking is set to standard. I don't see any other options that would let me come to a full stop using only regen. Am I missing something or are the cars just that different?
 

TMThree

Active Member
Mar 28, 2019
1,118
1,776
USA
Regen on model 3 doesn't bring you to a stop. It can't because regen stops doing anything at 5 mph.

Source: I own a model 3 and have driven 3 others.
 
  • Like
Reactions: android04

serendipitous

Member
Sep 10, 2019
397
638
Maryland, USA
Lobbing my opinion into the void: I also wish I could fully one pedal drive. Out of curiosity, anyone know if it's an electromagnetic impossibility to add electro drag down to a stop? Does it just become inefficient to have an inverter drag the motor down to zero?
 

woof

Fluffy Member
Supporting Member
Apr 30, 2009
1,588
1,904
Regen to full stop, and no rolling back, is one of the only things I miss from the BMW i3. True one pedal driving
 
  • Like
Reactions: Scott7

beatle

Active Member
Aug 31, 2019
1,268
724
Springfield, VA
Hmm, I was pretty sure the 3 would bring me to a full stop.

I figure this must be a software thing and not hardware. The 3 does have a permanent magnet in the rear, but I did not think the RPM would actually matter in being able to perform any regen.

Seamlessly transitioning from regen to mechanical brakes via software is a nice thought. Maybe that can be added in the future.
 

Tessaract

Member
Aug 12, 2019
337
338
Ottawa
Lobbing my opinion into the void: I also wish I could fully one pedal drive. Out of curiosity, anyone know if it's an electromagnetic impossibility to add electro drag down to a stop? Does it just become inefficient to have an inverter drag the motor down to zero?
The regen drag is proportional to vehicle speed. Mathematically, it's impossible for such an arrangement to bring speed to zero. However, rolling friction with (bearings, tires, etc.), as well as a slight application of "real" brakes might do the trick.
 

jerry33

(S85-3/2/13 traded in) X LR: F2611##-3/27/20
Supporting Member
Mar 8, 2012
20,025
24,855
Texas
Lobbing my opinion into the void: I also wish I could fully one pedal drive. Out of curiosity, anyone know if it's an electromagnetic impossibility to add electro drag down to a stop? Does it just become inefficient to have an inverter drag the motor down to zero?
If you have the system regen brake to zero, then some of the braking energy needs to come from the battery which reduces range. Also, if you don't exercise the brakes regularly, they will build up contaminants and rust (except for perhaps the $4K/wheel ceramic brakes), or they will have to drag all the time.
 

beatle

Active Member
Aug 31, 2019
1,268
724
Springfield, VA
I know from my days playing with electric RC vehicles, the ONLY braking available is regen braking and the motor had no problem bringing the vehicle to a halt in a hurry. Granted we're talking huge differences in scale, but the principle should remain the same.

The regen braking doesn't suffice for every situation - sudden stops or more aggressive driving require mechanical brakes.
 

Ande

Member
Jul 28, 2017
743
623
Norway
I know from my days playing with electric RC vehicles, the ONLY braking available is regen /QUOTE]

...wrong. the mass, gear ratio, and type of motor is not comparable.

For a full-size vehicle, you'll expect full stop, after nice and predictive deceleration. The only way to achieve it, even downhill, is software that apply reverse power to motor, or not to waste more energy, use friction brakes when regen energy is too low
 
  • Like
Reactions: Tessaract

Dithermaster

Member
Dec 27, 2015
580
394
Madison, WI
Sounds like maybe some changes in this area are coming soon? Elon said something about one pedal driving in the Q3 call, and some early access firmware seems to indicate that regen braking has changed. We'll see if it includes full stop.
 

dark cloud

Active Member
Apr 14, 2018
2,086
2,442
BC
I know from my days playing with electric RC vehicles, the ONLY braking available is regen braking and the motor had no problem bringing the vehicle to a halt in a hurry. Granted we're talking huge differences in scale, but the principle should remain the same.

The regen braking doesn't suffice for every situation - sudden stops or more aggressive drivinginertia

in a word: inertia. A good example is imagining having both a person and a mouse in identical ice skates pushed to an initial speed and released. The mouse will stop shortly while the person will coast for many metres. The larger mass (inertia) compensates for the frictional losses more so than the mouse.
 
  • Like
Reactions: Russell

ICUDoc

Active Member
May 19, 2015
1,747
1,227
Sydney NSW
the ONLY braking available is regen braking
This isn't quite true.
The battery is used in reverse to slow the car quickly, not just as a sink for current but as a source of reverse current.
In general, Teslas will now have motor braking down to ultra-low speeds after the latest software update.
 

Tessaract

Member
Aug 12, 2019
337
338
Ottawa
This isn't quite true.
The battery is used in reverse to slow the car quickly, not just as a sink for current but as a source of reverse current.
In general, Teslas will now have motor braking down to ultra-low speeds after the latest software update.
That's an interesting possibility. Do you have any source of (reliable) info that would indicate that "reverse thrust" is being used or introduced by Tesla in a recent SW release?
 

Merle

Member
Apr 5, 2019
166
160
Tahoe
Would the number of motors play a role?

A performance model with three motors would make me believe there would be more ability to recover the energy quicker. A base model with only one motor wouldn't have the same resistance.

So my question for the OP would be how many motors are in your vehicles?
 

ICUDoc

Active Member
May 19, 2015
1,747
1,227
Sydney NSW
That's an interesting possibility. Do you have any source of (reliable) info that would indicate that "reverse thrust" is being used or introduced by Tesla in a recent SW release?
Nope- was talking about RC cars, of which I have designed, built and raced many. Sorry, was not intending it to be a statement bout current Tesla mechanisms- although your question is an excellent one.
 

Products we're discussing on TMC...

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top