5_+JqckQttqck
Active Member
The front induction motor provides regens out of phase with the rear PM motor so they don't fight each other during acceleration. So, yes, you get some regen from the front - less than what the rear returns though.
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2019.8.3 Stronger Regen Over 30 MPH
- Thread starter GregD60
- Start date
The front induction motor provides regens out of phase with the rear PM motor so they don't fight each other during acceleration. So, yes, you get some regen from the front - less than what the rear returns though.
FelixtheCat
Member
Has anyone tested and compared regen feel of AWD vs. RWD? It seems to me that with 2 motors absorbing regen energy, one would feel stronger deceleration in AWD compared to RWD.
bd7349
Member
Yes, it’s been reported by many different people who’ve driven both that the dual motor Model 3 (and S/X) has stronger regen than the RWD model(s).
I've always been of the opinion that regenerative braking shortens your battery life. My Nissan leaf has 45,000 miles on it and now, only half the range (45 miles). I didn't understand the chemistry of these types of batteries and charged it daily to 100%
Trickl charging is easiest on a battery ( ie. 110v at 15 amps or regenerative recharging) and supercharging the hardest. Logic tells me:
if you're constantly charging and discharging the battery (driving using heavy regenerative braking) it's going to stay hot and burn out sooner. Also, it is particularly hard on a battery to charge it and discharge it at the same time.
My hope is to make this battery lasts b not running it below 25% and not charging it above 75%. Staying in The Sweet spot and charging at low voltage every couple of days when it needs it. Anyone have any more pearls of wisdom on battery life? I understand our model 3s have a newer generation of battery and I noticed the cells are physically larger. This must be in an attempt to reduce cost or????
You can't apply Nissan's problems to all EVs. Nissan made a number of mistakes, including their choice of chemistry and their decision to not thermally manage the battery.
Regen on a Tesla (about 70 kW) is about half as strong as what charging at a Supercharger is (145 kW and soon to be 250 kW).
Not running it below 25% will significantly increase the time it takes to do a long road trip. I routinely run ours down to between 10% and 15% in order to get the fastest speeds while Supercharging. Not charging above 75% will throw off your state-of-charge calculation due to not getting full cycles. This practice will end up frustrating you by making you think there's degradation due to the SOC calculation becoming inaccurate (mentioned in several threads and addressed by Elon in a Tweet recommending charging to 90%).
StealthP3D
Well-Known Member
We have a P3D (Stealth) and a Long-Range RWD that I switch back and forth between regularly. Any difference in regen amount is so small that I don't need to adjust the timing of when I ease off the throttle in different locations. They behave very similarly. I imagine if you hooked instruments up and measured it precisely you would see a difference but this difference doesn't play into normal driving much, if at all because the regen is normally modulated as needed, not slammed on full which would result in uncomfortably quick and sudden deceleration whether in AWD or RWD.
For that reason, I could never figure out all the teeth gnashing about reduced regen to begin with.
I made the same comment as the OP a few days ago wondering if anyone had noticed less regen since the last 3 updates or so (prior to 8.3). I have a RWD LR and live in So Cal where the temp is always about the same. For the last 3 months I noticed my car wouldn't slow down fast enough at stoplights (from 45MPH or so). I wound up having to apply the brakes at around 20mph instead of the 6-8mph range, Temps always in the 60s. Just got my 8.3 update notification, so fingers crossed it's stronger.
The OP's observeration makes perfect sense. The power improvements were due to increased tolerances on the battery and regen has always been power-limited. The reason regen is weaker at higher speeds is that kinetic energy scales with the square of velocity. The battery can only charge so fast, so the battery limits how fast you can draw down your kinetic energy. At higher speeds, that energy rate translates to less deceleration than at lower speeds.
The same effect is very apparent when accelerating - all cars become power-limited and their acceleration drops as their speed goes up. Regen is directly analogous to powered acceleration, so it makes sense that both would improve.
The same effect is very apparent when accelerating - all cars become power-limited and their acceleration drops as their speed goes up. Regen is directly analogous to powered acceleration, so it makes sense that both would improve.
I agree, ambient temps do not translate to pack temps. You can have a 70 degree ambient and a 50 degree pack easily.
Regen is not the issue on the LEAF or a Tesla. Your LEAF pack is being damaged by heat plus high SOC, you can do repeated high charges on a LEAF as long as you drive it and it is not hot. This is all very well documented on a LEAF. The model 3 is very sensitive to colder temps even in the 50-65 range, much more so than any other Tesla. I expect this to be adjusted soon with more data collection.
RFernatt
Solar/EV Owner/Enthusiast
I own (for now) a 2015 Leaf and I agree that regen is not the cause of the Leaf's battery issues. I always use B mode for max regen and it's still pathetic compared to the Tesla. I L2 charge the Leaf, but don't let it sit around at 100% for long either. In my case, the Leaf battery has held up well and I still have all 12 battery bars and the range may have dropped negligibly during my ownership, but that's about it. Leaf Spy still says things look good. Also agreed that hot climates, sitting at full charge, having the older battery chemistry and no thermal management is the real issue with Leaf packs.
Hmmm. Well I hope that those of us with a bit of chemistry education and a bit of EV experience can change your "opinion" on this. Because... this isn't subjective.
It is not fair to compare a Tesla pack to a Nissan pack. Batteries are not all the same just because they're called "Lithium". Many engineering decisions are made by each manufacturer. And Nissan is notorious for putting durability at the bottom of the list of priority. (In Nissan's defense, I must point out that safety of their packs has always been paramount. Point to a Nissan battery fire if you can. Yup... so there's your engineering decision that they made on purpose. It is always a compromise. Feel free to PM me if you need more info on Leaf engineering. I've been involved in that a bit more than most folks).
Regularly charging your Leaf to 100% was a much larger issue than any regen you used in the Leaf... especially considering how weak the Leaf regen is. And the lack of thermal management.
Trickle charging is *not* the easiest on a battery. There is a sweet spot for charge current... lowest is not the best because the *time* spent charging the batteries is not the pack's friend. The Tesla pack's temp is actively managed (unlike the Leaf's) and using regen generally is not going to overheat and "burn out" the pack sooner. And please note that it is chemically impossible to charge and discharge a battery at the same time. The chemical process can be reversed instantly, but never happens simultaneously. The more you regen, the less time you will spend charging it later. It is pretty much a wash in that regard.
You cannot charge the battery at low voltage. You can only charge it at lower current.
Tesla is famous for their batteries lasting longer than any other EV maker. It isn't just a "newer generation of battery." It is different than any other car maker is using. And Tesla's thermal management is outstanding. I wouldn't fret over only using half of your capacity. It's good to not charge to 100% all the time, and it is good to not drain it into the single digits regularly. But honestly... use the car and don't worry about it quite that much. You will want to charge to 100% now and again just to keep the SOC meter on target.
Just got 2019.8.3 this afternoon. Extra acceleration is noticeable, especially 30-60 mph. Regen felt smoother, there’s no longer a rapid increase in deceleration around 30. It’s almost like they started the extra regen at a higher speed in order to smooth it out. I didn’t notice a decrease in stopping distance.
Agreed. It's good to see that a number of people have noticed a similar change to what I experienced.
I understand the cold weather battery chemistry issues but there may be another consideration to think about... Did anybody ever see the notice that you should be very careful on icy roads to make sure when taking your foot off of the accelerator because regenerative braking could actually cause you to slide as though you'd hit the brakes? Is it possible that Tesla, in their desire to avoid being accused of causing people to crash at speeds over 30 mph, is updating/reprogramming the cars to limit regen during the winter?
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