Recuperation Mode Impact on Range

DJ Min

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I am trying to understand the impact of recuperation mode on range.

If I am reading the Good to Know app correctly, recuperation mode is slightly less efficient than having it off. I am thinking that is because when it is on, it sometimes initiates regen (forcing me later to draw from the battery to maintain speed) which is less efficient than just coasting. Putting the energy back in the battery and pulling it out has some small amount of energy loss compared to just coasting. However, if I am going down a steep hill, I am thinking there may not be a penalty to recuperation mode since I will likely be on the brakes anyway. In other words, going downhill recuperation mode is basically just automatically applying the brakes.

Does this sound right to folks? There isn't a lot of background on recuperation mode in the manuals. Thanks!
It all depends on what kind of driver you are. If you are an efficient coaster driving a combustion engine then you will be amazed at how efficient a coaster the Taycan is and you should definitely keep recuperation off. If you are an accelerator/braker (like my wife), or what I call a “gas guzzler” then recuperation mode is definitely for you. The Taycan will start recharging and start slowing you down which is what you need anyways because let’s face it—you are incapable of anticipating what’s ahead of you LOL ?…

…and of course if you are used to the single pedal feel and like it, use recuperation. I’ll still kick your butt in mi/kwh coasting, but you do you!

Of course, Porsche even has a happy medium for completely indecisive, neurotic people! Just put recuperation in AUTO mode! Let the computer decide whether to recuperate or coast. If the Taycan senses nothing ahead of you it will automatically coast. If it senses a car ahead of you (or tree or brick wall) it will automatically recuperate and start slowing you down. Best of both worlds.
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f1eng

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From an efficiency POV coasting and planning any braking to only use the up to 270kW of recuperation will be the most efficient.
When mild recuperation is used to simulate the familiarity of engine braking it rather depends on the efficiency of the motors as generators, it can't be 100% but is probably over 90% so not so bad.
If you use coasting but end up leaving the braking so late you need pads to hit rotors then all that energy will be lost as heat, so still not efficient.

The efficient way to drive is like piano playing legato not staccato.
 

XLR82XS

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From an efficiency POV coasting and planning any braking to only use the up to 270kW of recuperation will be the most efficient.
When mild recuperation is used to simulate the familiarity of engine braking it rather depends on the efficiency of the motors as generators, it can't be 100% but is probably over 90% so not so bad.
If you use coasting but end up leaving the braking so late you need pads to hit rotors then all that energy will be lost as heat, so still not efficient.

The efficient way to drive is like piano playing legato not staccato.
I do the opposite of ICE driving when in the Taycan and try to "ride" the brake pedal with gentle pressure as much as possible for recuperation and avoiding pad-to-rotor.

(P.S. I HATE people who ride brakes and prematurely brake WAY before a stop/traffic light. :swear:
 

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From an efficiency POV coasting and planning any braking to only use the up to 270kW of recuperation will be the most efficient.
When mild recuperation is used to simulate the familiarity of engine braking it rather depends on the efficiency of the motors as generators, it can't be 100% but is probably over 90% so not so bad.
If you use coasting but end up leaving the braking so late you need pads to hit rotors then all that energy will be lost as heat, so still not efficient.

The efficient way to drive is like piano playing legato not staccato.
Wait a sec. Pads don’t always hit the rotors when you brake?
 

f1eng

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Wait a sec. Pads don’t always hit the rotors when you brake?
Correct.
Unless in some sort of bed in part of the algorithm the braking ssystem does not use the pads and discs until deceleration by regeneration is at its maximum.
With a 270kW capability that is quite hard braking so actually it would be very easy to drive the car in a way which never used the pads on discs at all.
OTOH that probably does instigate the algorithm that cleans the discs, so it may be worth braking hard enough to use the discs from time to time.
A readout is available for power and regen level and until the regen maxes out the discs and pads are not needed.

Edit, there may be cars that do not use regeneration when applying the brake pedal, one pedal driving with regeneration only on closing the throttle is a cheap and easy implementation so could mean a cheap and easy braking system too but the Porsche (and fwiw my PHEV Prius) have sophisticated braking systems using regen and discs.
 


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Edit, there may be cars that do not use regeneration when applying the brake pedal, one pedal driving with regeneration only on closing the throttle is a cheap and easy implementation so could mean a cheap and easy braking system too but the Porsche (and fwiw my PHEV Prius) have sophisticated braking systems using regen and discs.
In our RAV4 Prime (PHEV), there is no one-pedal driving but when you coast, it sends electricity back to the battery at a high rate -- much higher than when charging the battery from the wall. When going down a long, steep hill, we can coast (the speed staying pretty much the same) for a mile or two and gain that much energy back into the traction battery (i.e., close to a mile of range via charging in a mile of coasting downhill).
 

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I’ve been using auto regen a lot which I like but I was thinking, if they used the traffic sign feature to turn on auto regen if it detected a red or stop sign, that would be awesome
 

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Here is what Porsche says about Recuperation (PRM). Apparently they call it recuperation and not regeneration.

Porsche Taycan Recuperation Mode Impact on Range PRM.JPG


A couple of points

  • Porsche often qualifies their descriptions such as up to 265 kw. So the number can be anywhere between zero and whatever
  • Up to 90% of all braking is done via recuperation and not by the friction brakes
  • Up to 90% of braking energy is recovered via recuperation
  • and a fun statistic
    • braking from 200 kph to 0 can add up to 4 km in range to the car
 


f1eng

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In our RAV4 Prime (PHEV), there is no one-pedal driving but when you coast, it sends electricity back to the battery at a high rate -- much higher than when charging the battery from the wall. When going down a long, steep hill, we can coast (the speed staying pretty much the same) for a mile or two and gain that much energy back into the traction battery (i.e., close to a mile of range via charging in a mile of coasting downhill).
My Prius PHEV does recuperate too and on the long descent from Snowdonia to Bangor on the A5 I gain about 9 miles of range! I am using recuperative braking as well as lift off recuperation though, and I use the gauge to optimise it.

The lift off recuperation in the Toyots hybrids was set to feel like engine braking in a IC car.

There is nowhere near the battery capacity or infrastructure in a PHEV to generate enough braking torque to have one pedal driving.

I have measured mine, the battery has 6kWh useable I don't know how much it can absorb short term but it won't be the 270kW max a Taycan could, obviously!
 

cometguy

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My Prius PHEV does recuperate too and on the long descent from Snowdonia to Bangor on the A5 I gain about 9 miles of range! I am using recuperative braking as well as lift off recuperation though, and I use the gauge to optimise it.

The lift off recuperation in the Toyots hybrids was set to feel like engine braking in a IC car.

There is nowhere near the battery capacity or infrastructure in a PHEV to generate enough braking torque to have one pedal driving.

I have measured mine, the battery has 6kWh useable I don't know how much it can absorb short term but it won't be the 270kW max a Taycan could, obviously!
Volvo has one-pedal driving in their new "Extended Range" XC60 T8 PHEV (18.8-kWh battery pack). Kyle Conner was impressed with it in his YouTube (Out of Specs) review of it last October.
 

f1eng

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Volvo has one-pedal driving in their new "Extended Range" XC60 T8 PHEV (18.8-kWh battery pack). Kyle Conner was impressed with it in his YouTube (Out of Specs) review of it last October.
Some people seem to like one pedal driving, I have tried it on a Jaguar iPace and didn't find it felt like a sports car the way the Taycan did.

I understand Tesla has one pedal driving so maybe those who are used to it prefer it or have just got used to it but I don't.

I like to feel like lifting off the throttle on any other sports car I have had.

My Husqvarna ride-on mower has one pedal driving and I have got used to it but don't actually like it.

The engineering reality is that since regeneration is less than 100% efficient it can never give as good a range as coasting.
Better to use regen for slowing down than the brakes though, obviously!
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