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7.0 Regen Reduced? Smoother? Less "Aggressive"?

Discussion in 'Model S: Driving Dynamics' started by GOPJEW, Nov 11, 2015.

  1. AmpedRealtor

    AmpedRealtor Well-Known Member

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    Why would Tesla make a change to regen ramp-up only in the AP cars? While I have a Classic and am not complaining that I have stronger regen than what AP owners are reporting, I wonder why Tesla didn't make the change uniform.
     
  2. Soolim

    Soolim Member

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    Because the APs are wimp.:tongue: Assuming by Classic you mean non-AP then maybe TACC for AP requires a modified regen for smoother deceleration? Hence, the regen modification is related to AP cars only?
    I think there is still room for Tesla to improve the regen by changing the regen profile, such as smooth regen from high speed and then applying more regen braking while the car is slowly coming to a stop, or when collision avoidance is needed. in other words, regen braking being inversely proportional to car speed if the driver simply lift off the accelerator pedal.
     
  3. gavine

    gavine Petrol Head turned EV Enthusiast

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    Every time I do a firmware update, I find myself checking the regen setting to make sure it isn't on low. I would bet that the current standard regen is about the same as the original low was before.
     
  4. Soolim

    Soolim Member

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    Similarly, I find myself lifting the go pedal earlier to arrive at the stop sign with less than 5 kph.
     
  5. rallykeeper

    rallykeeper Member

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    Loaners are wonderful test cases for these issues.

    I have a non-AP P85 loaner right now with the .56 version of 7. My normal car is a 2012 non-AP S85 with the same software.

    The P85 has noticeably stronger regen. First thing I noticed when I drove it yesterday.

    I can't seem to find it in the forums, but I recall that the v5 or v6 upgrades years ago had a similar effect on regen. However, there were no changes in the software itself -- it's just a bug that appears during installation on some cars.

    There was a multi-step process to cure your MS. It went something like: (a) change regen to low; (b) drive; (c) reset the center screen and the driver screen; (d) change regen to standard; (e) reset the center screen and the driver screen; (f) all fixed.

    I'm pretty sure I don't have the steps quite right.

    Anyone else recall that fix? It definitely worked last time this happened.

    My SC is applying the latest software updates, so I may not have an issue when I get my car back. If I do, I'll try the restart process to see if I can figure it out.
     
  6. Soolim

    Soolim Member

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    Can you please be more specific on what the (a) to (f) steps fixed?
     
  7. Cyclone

    Cyclone Cyclonic Member ((.oO))

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    Without saying this actually happened with regen, rallykeeper seems to be describing the situation that has happened with various settings in past updates. Sometimes, a setting will be on A, but the screen says B. Rebooting usually fixes odd behavior, but sometimes, owners have had to switch from "B" to "A", reboot, the go back from A to B. I had this happen to me with my Spotify settings between Normal vs. Best quality.
     
  8. rallykeeper

    rallykeeper Member

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    That's exactly right. By running through those resets of the regen setting after prior updates, I somehow brought standard regen back to life.

    Unfortunately, I can't test it this time since my car came back from my SC with .77 and now regen seems to be working better. (Of course, I also had my drive unit replaced, so this may have been the source of my own regen problems...)
     
  9. Shaggy

    Shaggy Member

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    Honest question from a non-owner... I have a Ford Energi, 'she' regens from the motor (coasting) and brakes. I have a low and high motor regen and the first portion of brake pedal pressure is for regen before the physical brakes take over. I get a 'braking score' each time showing % of energy returned of the possible. In 'drive' I have normal regen and in 'low' it is just a higher regen rate, not a true low gear as I have a CVT.

    So... does the Model S do that as well? I.E. The harder you break, the more regen until the brakes hits a threshold and then engages physical braking?
     
  10. roblab

    roblab Active Member

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    No. Regen and braking are completely separate. Regen does its thing. Braking is determined by you, usually in the last ten feet to the stop sign. Unless you don't pull your foot off soon enough, but it's still your job to brake, and it doesn't affect regen.
     
  11. BertL

    BertL Active Member

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    As roblab suggests, braking with a Tesla is different than what you know with your hybrid -- at least it is from my having driven Lexus RX Hybrids the past 10 years... "Regen and letting-up on the accelerator pedal" is the single thing I made the most comments about during my MS test drive -- maybe half a dozen times -- probably because how accustomed I was with my Lexus hybrids. If your hybrid operates like both of mine did, regen occurred for the most part on the downhill, coasting, AND as you apply the brakes -- with slowing as you take your foot off the accelerator being a relatively placid thing much like it is with a traditional ICE. OTOH, MS does not regen when using the physical brakes. Instead, MS drivers that care about maximizing regen and therefore range, will learn to drive a little different as roblab suggests -- as strange as it may be to non-race-car-drivers, largely using the accelerator pedal to speed-up and slow-down, reserving the true brake pedal for emergencies, the last few feet coming to a stop, and to hold yourself in place (I won't take us off-track describing "vehicle hold").

    On MS today (V7.0 firmware), regen has two settings.
    1. One that IMHO is much softer and feels more like, and slows MS more like, what I knew with my former hybrid as my foot came up off the accelerator
    2. The other setting (Standard) is what I suspect most MS drivers use (including me) the majority of the time. It slows MS MUCH more abruptly/powerfully/agressively than what you know in your hybrid. As you've seen in this thread, V7.0 of the firmware may have made some changes to this particular setting that some what I'll call "longer-term owners" want to be even more aggressive than it now appears to be. For me now, the accelerator pedal isn't quite so much of a "trigger pedal" (aka "trigger finger" if you know what I mean), and while it aggressively brings my MS to a stop as I let up on the pedal, I (and especially infrequent MS drivers) IMHO can drive more smoothly than the former 6.2 release I had for less than 10 days after having taken delivery of my new S90D...
    When you take your first MS test drive some day, having come from a hybrid, you'll immediately get what I'm saying. Be sure to experiment a little: First, be sure the Regen setting is on Standard, then when no one is in front of you and not on your tail, as you are coming to a stop, note how rapidly MS will bring itself to a stop opposed to what you are used to as you release the accelerator pedal much faster than you are used to doing. THAT aggressiveness is providing regen as MS pulls itself to a stop... You can then play with being a bit more elegant releasing the accelerator pedal just a little as you approach a stop and see the effect... Hope that much longer and not as to-the-point explanation (kudos to roblab) helps further your understanding.
     
  12. Shaggy

    Shaggy Member

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    Actually done two test drives now... At the Billion mile one I played with the regen on low which is what I was used, getting off the battery sooner and coasting more. My PHEV encourages brake regen over motor regen. As I apply more brake, I get more aggressive regen from the brakes to a point the physical pads take over and aggressively stops the car. I've appeared to ride my brakes for a while slowing the car but really just charging my battery.

    So the Model S doesn't have regeneration on the wheels/brakes, just the motor? It was my understanding both cars did both or am I not following you correctly.

    Your standard regen is my car's 'low gear'. When I press on my brakes I'm actually regenerating from two things, the motor and the brakes; until I press too hard and the physical brake engages. Again, this is my best understanding.

    I've been reading about how fast you pull off the accel matters which is again like my car's fake low gear. If I feed a little amount of accel, but not so much as to actually push the car, it still is enough to disable the regen from the motor, so I coast farther. In stop and go traffice, I shift into low and then single pedal drive. I REALLY like being able to nearly instantly shift into higher regen (light turning red).
     
  13. trils0n

    trils0n 2013 P85

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    All regenerative braking happens in the motor, in any electric or hybrid. Regenerative braking = using the motor as a generator. Most (all?) hybrids map this regen on the first amount of travel of the brake pedal. Tesla does not. Tesla's brake pedal controls only the friction brakes. The accelerator pedal activates regen by lifting off.
     
  14. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    There's no reason to switch from standard. It's just like acceleration, only in reverse. You modulate the accelerator pedal to get the amount of deceleration you want.

    As TrilsOn said, all the regeneration is on the accelerator pedal. This had two advantages (besides the almost one pedal driving). First it's far simpler than the complexity required to have regen on the brake pedal. Second, there is no transition when regen stops (as in going over an expansion joint or pothole while braking) so it's a far smoother braking experience.
     
  15. BertL

    BertL Active Member

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    #75 BertL, Dec 7, 2015
    Last edited: Dec 7, 2015
    OP, I agree with comments others have provided since my last post... The key thing here to me difference-wise moving from my Lexus Hybrids to my MS is, if you care about a smooth transition as you come to a stop, you have two options in the MS: "Low" is much more like my former hybrids in the way lifting off the accelerator pedal was a piece of cake transitioning from what I owned to what I now have sitting in my garage; "Standard" requires a bit more finesse in every interaction to accomplish a very smooth transition to a stop like an ICE or hybrid can generally provide without a lot of effort if you're not in a panic stop. Others will disagree, especially if they have driven MS for a long time or didn't come from a hybrid, but that is my own personal opinion having driven two very smooth Lexus hybrids for 10 years before replacing them with my MS. After trying both regen options on my MS, "Standard" is still what I elect to use because of its benefits in Tesla's implementation, and I deal with the sometime jerkiness it entails (the hopefully few times) when I'm not paying 100% attention before I need to come to a stop a little sooner than I would like (but far from being in any panic stop sort of situation.)

    FWIW, my Retriever who often rides in my back seat on her canine cover is a sensitive girl. After 2 months, she honestly does not like the ride in my MS as much as "her" former Lexus RXh. Perhaps that is because the driver (me) has not become as adept at using the trigger-accelerator-pedal for the slow downs; Perhaps that is because she does not feel as comfortable turning around in the back seat while I'm traveling because the seat backs don't retract as much so she does not feel she has enough space to move her 65-pound body around; or maybe it's because she also has to sit further inside the vehicle because the way the seats and interior side panels are oriented to give more room for humans. Be that as it may, IMHO, it's to a large degree because "Standard Regen" is just a little bit harder to provide that "chauffeur-like" experience as you come to a stop, and I've not yet accomplished it in her mind, even though I've yet to have a human passenger make a comment. Me? Every now and then I notice the difference in MS regen aggressiveness as I tried to explain earlier, acknowledged it in my first test drive, and now just accept it as part of my new MS that I really enjoy.​

    Glad to hear you've had a couple of test drives. Good luck with your decision.
     
  16. Cyclone

    Cyclone Cyclonic Member ((.oO))

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    One thing to note when comparing those of us who get smooth stops in the Model S, even when using the brake, is that pre-AP cars had traditional hydraulic brakes while AP-capable have electromechanically engaged hydraulic brakes, making them much more grippy in my opinion. There was some play in the older style brakes that I do not experience in loaners, but part of that could also be less experience with those brakes compared to my last 10k miles in a pre-AP S.
     

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