One pedal drive (vs) Brake regen

[awp0]

Since 1pd driving is not 100% efficient anytime you are using regen you are negative net vs simply coasting. You coast anytime you are not on the gas or the brakes. If you’re used to driving with 2 feet like my brother then there is no coasting. Either gas or brakes all the time (which is 1pd), and then your passengers puke and one get the deserved label of bad driver.

Yeah, but I guess my point is that it gets more complicated if coasting requires that you to use the mechanical brakes more often compared to 1PD. I wouldn't be able to coast very well in most driving situations, without using the mechanical brakes quite a bit (way more compared to 1PD).

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[AKgrampy]

Yeah, but I guess my point is that it gets more complicated if coasting requires that you to use the mechanical brakes more often compared to 1PD. I wouldn't be able to coast very well in most driving situations, without using the mechanical brakes quite a bit (way more compared to 1PD).

Don’t forget that for the most part you are using regen and not mechanical braking in 2 pd mode. The regen is just less aggressive.

 

[awp0]

Don’t forget that for the most part you are using regen and not mechanical braking in 2 pd mode. The regen is just less aggressive.

I've heard different descriptions of this. Is it true that the MME's brakes are "mostly" regen? Others have described it as regenerative only in the very beginning of the braking curve, transitioning to mechanical after that. I guess that would be an important thing to understand when comparing the efficiency difference between Whisper/2PD and Unbridled/1PD (opposite sides of the spectrum I think).

 

[67mustang]

Since 1pd driving is not 100% efficient anytime you are using regen you are negative net vs simply coasting. You coast anytime you are not on the gas or the brakes. If you’re used to driving with 2 feet like my brother then there is no coasting. Either gas or brakes all the time (which is 1pd), and then your passengers puke and one get the deserved label of bad driver.

I guess if you're a bad driver and have no throttle control you'll make passengers sick... otherwise OPD can be as smooth as 2PD

 

[AKgrampy]

I've heard different descriptions of this. Is it true that the MME's brakes are "mostly" regen? Others have described it as regenerative only in the very beginning of the braking curve, transitioning to mechanical after that. I guess that would be an important thing to understand when comparing the efficiency difference between Whisper/2PD and Unbridled/1PD (opposite sides of the spectrum I think).

If you are smooth it is 100% regen. The brakes only engage to hold right when you stop. Sometimes you can feel them engage. Obviously if you apply the brakes too much they will engage a bit. I have found that I have become a much smoother driver since acquiring my Mach.

 

[awp0]

If you are smooth it is 100% regen. The brakes only engage to hold right when you stop. Sometimes you can feel them engage. Obviously if you apply the brakes too much they will engage a bit. I have found that I have become a much smoother driver since acquiring my Mach.

Thanks! That's great news, and seems like it would mean that people should choose between 1PD and 2PD based on comfort/preference rather than trying to overthink the efficiency tradeoffs (like I've been doing!).

 

[AKgrampy]

Thanks! That's great news, and seems like it would mean that people should choose between 1PD and 2PD based on comfort/preference rather than trying to overthink the efficiency tradeoffs (like I've been doing!).

Exactly right! I may give 1PD a try next summer. Not willing to switch on icy roads. I did give Whisper a go because others said they liked it in snow but there was too little of the regen slow down for me so that braking on the snow and ice did not feel right.

 

[JamieGeek]

Since 1pd driving is not 100% efficient anytime you are using regen you are negative net vs simply coasting. You coast anytime you are not on the gas or the brakes. If you’re used to driving with 2 feet like my brother then there is no coasting. Either gas or brakes all the time (which is 1pd), and then your passengers puke and one get the deserved label of bad driver.

You do realize that when you're driving in 1-P mode that there is a throttle position that is coasting right?

You don't PWM drive in 1-P--you'll give everyone whiplash, a headache, and will have to clean up vomit out of your once fancy Mach-E.

Thus when driving down the freeway in 1-P and you want to coast you don't remove your foot from the throttle, instead you move it to the coast position (its somewhere around 10%). Likewise moving the throttle to 9% is a little bit of regen, 8% is a little more, 7% is even more, until you get to 0% where you have full 1-P regen.

On the Mach-E this is the reason that 1-P and using the brake are equally efficient (if the driver is actually aware that the throttle goes from 0-100% and isn't simply a boolean value).

 

[devmach-e]

The c rating of the battery. No battery can act like a capacitor with instant discharge and recharge with near 100% efficiency. Porsche does regenerative braking just not 1pd which causes a negative net vs simply letting off the gas and coasting. 1pd is like driving with 2 feet you are either accelerating or decelerating and since we know regen isn’t 100% efficient then 1pd is not the most efficient way to drive a car. Especially on the freeway also not very comfortable for your passengers. Go brake go brake go brake go brake puke ?

When a Porsche driver hits the brake pedal, up to 265 kW goes into the battery. The battery can take that higher than 1C rating for a short period of time.

I’ve been using 1-pedal in the MME since I got it, and in my previous car, a Bolt EV, without any issue. I figured out a long time ago how to feather the accelerator pedal and not induce whiplash in my passengers. It isn’t clear to me whether 2-pedal is more efficient than 1-pedal.

 

[Space Ghost GT]

You do realize that when you're driving in 1-P mode that there is a throttle position that is coasting right?

You don't PWM drive in 1-P--you'll give everyone whiplash, a headache, and will have to clean up vomit out of your once fancy Mach-E.

Thus when driving down the freeway in 1-P and you want to coast you don't remove your foot from the throttle, instead you move it to the coast position (its somewhere around 10%). Likewise moving the throttle to 9% is a little bit of regen, 8% is a little more, 7% is even more, until you get to 0% where you have full 1-P regen.

On the Mach-E this is the reason that 1-P and using the brake are equally efficient (if the driver is actually aware that the throttle goes from 0-100% and isn't simply a boolean value).

The throttle pedal is pid tuned. There is no magical set point for coast through its travel in 1pd.

 

[Space Ghost GT]

When a Porsche driver hits the brake pedal, up to 265 kW goes into the battery. The battery can take that higher than 1C rating for a short period of time.

The rest will get burned off as heat in the inverter so it’s not 100% efficient!!!!!!

 

[devmach-e]

The rest will get burned off as heat in the inverter so it’s not 100% efficient!!!!!!

No regenerative braking is 100% efficient, including the MME. But the efficiency of the internal charger/inverter is pretty good at better than 90%. Better to recover most of the kinetic energy via regenerative braking than to waste it all as heat from friction braking only.

 

[JamieGeek]

The throttle pedal is pid tuned. There is no magical set point for coast through its travel in 1pd.

However you have to agree that somewhere in between full regen and acceleration that there is a theoretical 0 point--there has to be the line/curve/etc. crosses the axis in 1-P mode. Even if open-loop or full feedback controlling it still goes from accel to decel.

 

[devmach-e]

The throttle pedal is pid tuned. There is no magical set point for coast through its travel in 1pd.

If you feather the pedal correctly you can essentially “coast” with very little power going in or out of the battery. Sadly the MME doesn’t have a kW display on the dash to see this, but CarScanner can show it.

 

[Space Ghost GT]

However you have to agree that somewhere in between full regen and acceleration that there is a theoretical 0 point--there has to be the line/curve/etc. crosses the axis in 1-P mode. Even if open-loop or full feedback controlling it still goes from accel to decel.

You said it. It’s there somewhere but trying to find it is not something that will easily accessible. So your in am either or situation in normal driving.

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