Yeah, I suspect you're right, I do prefer the feel of the Tesla to the Volt (which uses the half-n-half approach). For efficiency on the highway, though, it seems like it'd be nice to have the option to enable it.
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Regen Changes in New Firmware?
- Thread starter docgarner
- Start date
Yeah, I suspect you're right, I do prefer the feel of the Tesla to the Volt (which uses the half-n-half approach). For efficiency on the highway, though, it seems like it'd be nice to have the option to enable it.
gavine
Petrol Head turned EV Enthusiast
Most people don't like regen when they first get the Model S but very quickly learn to love it. However, if there was an OFF setting, people wouldn't give it a chance and just turn it off the first day and out the window goes the advantage of regen indefinitely. I think having two settings is smart because after you get used to "low", you might venture up to standard and then keep it there.
If the ms had more regen to make then allowing the brake pedal to make electricity instead of brake dust would be great. As it is because the car is so heavy and the battery can only be recharged by regen so fast, it appears that the regen braking effect is limited to the moderate amount which is usually fine to have triggered by the accel pedal lift off.
But if there were additional regen available it would great to have that triggered by the brakes. Everything would be exactly as it is now except the brakes wld make electricity instead of brake dust. The I booster brakes would easily modulate the regen from the brake pedal. Even without ibooster Toyota and Lexus has had regen on the brake pedal just fine.
And my experience is that while Toyota has gotten much better at the integration of brakes + regen, it's still herky-jerky compared to the Model S.
After 2 1/2 years with Model S, I've grown accustomed to knowing when to slow down and aside from emergencies I really use the brake only for the last 5 mph. I'd actually like 90 kW of regen if it could be mustered. I suspect, though, that the engineers find that too risky - the 85 kWh supercharging taper curve goes below 90 kW at 40-45% SOC, so they must be concerned with charging at that rate at anything above 140 miles rated or so.
In my many years with three toyota/lexus hybrids, the regen on the brakes worked perfectly. And they did it without iboosters. Now with iboosters it is automatic. TACC already applies brakes with both regen and old style -- no problem.
I do wish that Tesla would allow additional regen to be triggered from the brake pedal and was hoping that the ibooster would allow them to do that but alas, no.
[before anyone replies in anger that you don't want them to take away regen from the accel, re-read what I wrote -- nevertheless someone is bound to skip this part]
I really do wonder why the regen is limited as low as it is; 60 kW compared to 45 kW on my Volt, which has 1/5th the capacity of the MS. (Though I do realize that GM uses a chemistry that's more tolerant of power surges relative to the size of the battery.) Even if we look at the supercharging taper curve, I think it's also important to consider that supercharging is a prolonged (30 minutes+) charge while a regen charge is going to be much shorter in most cases. Then again, maybe it's exactly those cases where the regen would be rather prolonged (steep hill descents) that they're worried about...
breser
AutoPilot Nostradamus
TES-E
Member
Hmmm... Thanks for all your thoughts. My personal experience is similar to that of a poster on the 1st page; the car now seems to have a "wait" period at 30kW or so before moving on to harder regen. And I'd think the regen limit is because as a 3-phase motor, the powertrain regen can only create AC. That would then have to be rectified into DC to return to the battery. Not sure if they're using the circuitry of the inverter or the car's built-in charger(s) (I assume the former since each charger is limited to 10kW) but there's probably a limit at this level.
Solarguy
Member
My wife and I have both noticed a decrease in regen starting about a month or so ago. The difference is distinct enough that we both checked screen settings to be sure we had max regen turned on thinking it was inadvertently changed to low. We both miss the more aggressive regen and can only hope that a future software change will add a third button to select max regen to give us back the regen feel we were so used to and liked.
If you noticed the change after a recent software update, I would ignore it because it didn't really happen.
I've been saying this for awhile too, but I have zero data to support it. It may be the difference between dual motors and one (I upgraded). I used to be able to drive one pedal most of the time. Now I use the brake more.
doctorwho
Active Member
roblab
Active Member
All I have is my memory. When I got my car, the regen arc went to 90 kW and some over. I have the old A battery, and superchargers only go to 90 kW max with my car, whatever that's worth. But I definitely noticed a difference -- to weaker regen -- about 6 months ago. They ALSO changed the curve of regen, so it sneaks into it gently, so there is no neck snapping. I understand some hate to have the car drag back when they pull the foot off the pedal.
I was interested when a friend bought a Tesla and was complaining about regen. I told him he could control it with his foot. He didn't know that.
I have asked Tesla to give us a "High" button to go along with the standard and low choices.
More people should write them.
If they are trying to save the battery, well, then, tell us. Otherwise, those who don't like regen (used to driving automatic tranny cars) can use low, and the ones who like to have the car slow down, let us do it.
You are the only person that I have ever seen say that their regen went to 90kw including Signature owners. Now I'm sure there are those with REST data that could correct me if I'm wrong. As for me I've had mine since early 2013 and have never seen anything above 60kw, well maybe slightly above. Now they did change the scaling on the speedometer/energy gauge after one of the updates (6.2?), are you sure that's not what you remember?
I don't remember having regen or acceleration limited by a cold battery pack the first winter or two. Same with my Leaf. Now on a cold day with more than 50% charge, the Leaf barely slows at all, but I think they moved some of the Leaf's regen to the brake (which I hate -- makes the brakes incredibly grabby).
mknox
Well-Known Member
About a year ago, I started to notice that no matter what, I couldn't get above about 45 kW of Re-Gen. Even if I dropped my foot right off the accelerator at 75 MPH. I also noticed I was getting nowhere near 90 kW at Superchargers even when the battery was very low. Tesla couldn't really find anything wrong. Then I had a main pack contactor failure and the car was in for a week while they dropped the pack and undertook repairs. After getting the car back, my re-gen and Supercharging were all back to normal. I'm not sure what the connection is, but it was as obvious as day is to night.
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