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Regenerative braking vs brake pedal

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Without being able to get into technicalities, I feel like I understand regen braking when I let up on the accelerator.

What about the brake pedal? Is it purely traditional friction braking? Or is a certain percentage (or perhaps "initial stages") of braking achieved via regen through the pedal, too?

Prior to my MS, my only experience with regen braking was in my aunt & uncle's Prius. The brake pedal on that car blends regen & friction braking. Different car, obviously, and the hybrid vs all-electric is only the most obvious difference. But, such a "blended" system is out there....

Is there any such mixture going on in our cars?
 
With only 60kW of retard working a 4800lb car, the friction brakes are doing a lot of the work.
The brake pedal on a Tesla AFAIK provides no regen like you see on some other EVs.

The term is 'blended-brakes', which is when the brakes augment the regen. A classic example of this is seen in the 3600lb Chevy Volt, which also has 60kW of regen. Lifting the accelerator can provide ~45 kW, IIRC, but to get the rest of it, you need to use the brake pedal.

Why do they limit accelerator pedal regen? Traction. You don't want to skid the tires in low traction. Brakes use ABS which is better for control.
 
Regen is aggressive enough that I rarely use the brake pedal at all. Tesla-owning friends report similar experiences.

Coming from a Fiat 500e, I was used to blended braking, and still wish Teslas had that, but once you get used to using the regen when you take your foot off the accelerator, the result is probably very similar to what we'd get with blended braking.
 
At first, I really could not understand why my MS does not have blended braking. Coming from smaller and way less expensive Ev's I assumed it would have a heat pump heating system and control of regen braking through the brake pedal.

In reality, I find the 'one pedal driving' approach that Tesla adopts as quite natural and actually rewarding as it promotes smoother, more economic driving, paying better attention to the road ahead for slowing down and a more connected feeling with the car.

Where that falls apart is when you have little or no regen available due to battery status and of course FSD / AP has yet to learn how to read the road ahead and preemptively slow down.
 
Yes, they can/do work together and simultaneously.

Lest the answer already posted is forgotten, YES, just friction brake.

If you brake hard, you effectively stop / override regen braking but depressing the brake pedal doesn't in itself turn off regen.

Ah, I think I’ve got it!

So: the brake pedal itself does not apply or increase any regen braking. It solely applies mechanical/friction brakes. HOWEVER, by having one’s foot completely off the accelerator, one is already getting maximum available regen, and the two are additive. Yes/no?

@Battpower, not sure what you mean by “effectively stop / override regen”—could you expand, please?
 
Ah, I think I’ve got it!

So: the brake pedal itself does not apply or increase any regen braking. It solely applies mechanical/friction brakes. HOWEVER, by having one’s foot completely off the accelerator, one is already getting maximum available regen, and the two are additive. Yes/no?

@Battpower, not sure what you mean by “effectively stop / override regen”—could you expand, please?

Technically I doubt you are actually stopping regen from acting by braking hard, but in my other small EV I can see very clearly that when you brake hard regeneration reduces.

In any event, if you care about recapturing energy, gentle deceleration works best.
 
Technically I doubt you are actually stopping regen from acting by braking hard, but in my other small EV I can see very clearly that when you brake hard regeneration reduces.

In any event, if you care about recapturing energy, gentle deceleration works best.

Yes. But friction can dump energy far faster than regen. so overall braking energy dissipation can easily skew to friction.

Absolutely understood. Thanks again, great discussion!
 
Technically I doubt you are actually stopping regen from acting by braking hard, but in my other small EV I can see very clearly that when you brake hard regeneration reduces.

In any event, if you care about recapturing energy, gentle deceleration works best.

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.
 
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.

With blended brakes it does as total braking is compared with accelerometer data.

I agree that with non-blended it is just because the energy is being dissipated not captured in the regen system.
 
Prior to my MS, my only experience with regen braking was in my aunt & uncle's Prius. The brake pedal on that car blends regen & friction braking. Different car, obviously, and the hybrid vs all-electric is only the most obvious difference. But, such a "blended" system is out there....

If you want really "out there" my EZGO RXV has no brakes; no pads, no shoes, it brakes solely by regeneration, when you press the brake pedal it regenerates, until you crank on the brake pedal so hard the park brake engages. And the park brake engages automatically every time you stop; you don't have to engage it. This technology is 12 years old already.
 
If you want really "out there" my EZGO RXV has no brakes; no pads, no shoes, it brakes solely by regeneration, when you press the brake pedal it regenerates, until you crank on the brake pedal so hard the park brake engages. And the park brake engages automatically every time you stop; you don't have to engage it. This technology is 12 years old already.

The parking brake engages automatically for us, too ("hold mode" / ((H)) is the same physical braking mechanism as the parking brake, yes?).

Re "how hard" the regen can brake: I have no idea of the physics behind it--I guess it's a design decision to limit it...?
 
I've heard that battery can only take so much power from regen at one time. Barring the new Maxwell battery rumors and/or supercapacitors, I think the battery is the current limitation in how much regen can be applied/absorbed at one time.

If you want to see an example of this, see how your regen works in cold weather. It will be much less effective than when the battery is fully warmed up and "optimized" to absorb maximum power
 
The parking brake engages automatically for us, too ("hold mode" / ((H)) is the same physical braking mechanism as the parking brake, yes?).

Re "how hard" the regen can brake: I have no idea of the physics behind it--I guess it's a design decision to limit it...?

The parking brake is not applied using the H hold feature, which means the brakes are actuated hydraulically. No idea if it just the front, the backs, or all 4 though. I assume all 4 same as using TACC/AP.
 
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