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Tesla owners: How strong is regenerative braking?
- Thread starter insaneoctane
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- Model 3
Depends on the speed. i3 has better rolling resistance and the Model 3 has better aero. I expect the efficiencies to cross over at around 50 mph, where the Model 3 is more efficient above this and the i3 is more efficient below this.
i3 has a 0.29 drag coefficient. Is the frontal area really that small?
ChrisL said:
Yes, hence the question about how hard that is to do
BerTX said:
For the record, I enjoy hypermiling. If you don't think it's fun, nobody's holding a a gun to your head and making you do it
CarlitoDoc
Member
Stupid Question : Has anyone ever hit the P button by accident while driving? I have not had any vehicle with a steering column mounted shifter, so I wonder.
On the S you have to give it a pretty good push, so no. Also, it's Mercedes hardware on the S, I don't know if they are similarly outsourcing the Model 3 stalks.
It's all computer controlled, it won't let you switch to park (or reverse) if there is a chance to damage the car.
A long press of the parking button should activate the emergency brake. I believe a few people on the forum have tried it and confirmed that. I haven't tried it yet.
busaman
Member
my last car was an i3 and i avereged arround 3.8miles per kw hour my p85d averages arround 2.8-3.0 so for the size and weight it is fantastic and i do drive it much faster than i did the i3 bothe are great cars...
Can you explain this use case?I'll probably end up doing that a lot
If there's a red light in front of you, in a Tesla, you pull your foot off the pedals, and you usually get about as much energy as you can back into the battery. It's unclear to me how a lack of regen would help. If you're on the freeway, and you go down a hill, you let up on the go pedal and drag slows you down to the proper speed. If you're on the freeway and some d-bag cuts in front of you, you put your foot on the brake. Trying to save a couple Joules isn't worth endangering people.
and while regen isn't perfectly efficient, 1 kW of regen vs. 0 kW regen is basically irrelevant as regen is > 80% efficient. Do that for 1 minute every trip, and you save yourself like 3 Wh, or maybe $0.0006 per trip yee-haw.
and yeah, sometimes the car can give you 30 kW of regen, but in those cases, you presumably actually want to be slowing down (e.g., red light approaching). Your #1 responsibility as a driver is to drive well, not to drive efficiently.
I guess I never really find myself feeling the need to coast.
Try it; it's really much less dramatic than you might expect. Seems like less braking power than regen. It's certainly not like your car will suddenly be full braking; it's a very mild deceleration.
That is basically the gist. Since regen isn't 100% efficient you don't want to "waste" energy by unnecessarily exerting it only to regen not all of it back up. I was pretty active on the LEAF forum when I had mine, and this is how people get 5 to 6+ mi/kWh. Some of them had to for range purposes, but others just like to do it. Serious hypermiling requires attention and skill. I found it's much more enjoyable to drive worry free, thouogh. Of course, YMMV (pun intended).
As you know, hypermiling in an EV is different than in an ICE. Putting the Tesla into low regen (more coasting) will let you "float" more (like an ICE), but I expect you'll end up using the friction brake more often. Net, you'll probably come out ahead by modulating the accelerator pedal to its neutral position when you want to coast. It's pretty easy, and you have a very visible display in the dashboard letting you know when you reach that zero point. Then, you still have the full regen available when you actually want to slow down, without the touching the friction brakes.
Don't panic when you go into regen. Yes, you are not being as efficient as you could be, but you do get some 80% of the energy back. A day or two later your right foot will get the hang of where that zero point is, and you can hypermile to your heart's content.
Don't panic when you go into regen. Yes, you are not being as efficient as you could be, but you do get some 80% of the energy back. A day or two later your right foot will get the hang of where that zero point is, and you can hypermile to your heart's content.
LoL Rick
Like Buttah
Regen is something like 65% efficient, not 80%. But I agree that it really is not worth the extra effort to avoid it, and it many cases it is unsafe. No brake lights means you are more likely to get hit. Just yesterday I had to turn my regen from normal to low so that I could use the brake to force the brake lights on. The person behind me nearly hit me 4 times because she wasn't paying attention in stop & go traffic.
Garlan Garner
Banned
DrivingRockies
Closed
Yes, safety built-in. It doesn't so anything. Hold down for a good ride.
In my model S at highway speeds, you can lift off the accelerator completely, and see that regen shoots to its maximum of about 60 kW/h and the experience felt right then is negligible deceleration force. It seems to hardly be slowing, speedometer holds steady... hardly dropping at all. So you're covering a lot of ground soaking up juice.
This is about 80 braking horsepower/hour of reverse thrust ... and you feel practically nothing. Because the car is heavy and has a heck of a lot of inertia.
Until the speed does start to drop a bit... then things change if you keep off the pedals. Tesla has tuned regen so that it does not maintain maximum reverse thrust as the car slows... it eases up on the regen captured as the car slows. Power flowing backward into the battery begins to drop BUT the effect felt is ever increasing deceleration force because the car is now also decelerating more aggressively -- your body starts to press forward more into the seat belt. To a point. Whereupon, regen capture starts to relax at a more rapid rate... You then feel the car starting to slow less aggressively but still, quite firmly, and your body starts to settle back into its seat easing off the seat belt. Until finally (we're talking at very low speed now) the car just "gives up" on regen and you coast-crawl as if in neutral until road friction stops the car, or you touch the brake.
That's the experience of a highway decel with regen coming to a complete stop.
It's interesting to watch the car icon on the dash to see when brake lights come on and when they go off. All without ever touching the brake pedal. This auto-brake light is not purely related to deceleration force, but is also tied to speed and regen rate... methinks.
Overall, regen feels weird for the first 3 times, then its expected and feels completely natural. Soon, you begin "timing" your decel lift off while choosing a desired stopping point ahead, and make a game of it -- avoiding the use of friction brakes for anything other than the last foot of "stoppage" required at a STOP sign. If you're on a slight incline, bonus points if you can do the whole true stopping experience and go again, without ever touching the brake pedal.
Then you drive an ICE car again... and holysh*t when you lift off the gas pedal, that car feels like it's slipping on a greased road out from underneath you. And suddenly you remember what a brake pedal is for.
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brucet999
Active Member
I use regen as much as possible. I found it not as strong as with the Bolt I test drove, but quite adequate for effortlessly smooth stops. Compared to ICE vehicles, necessarily using their friction brakes, I start slowing earlier - maybe twice as far back from the intersection - than most cars around me, probably earning grumbles from impatient following drivers who want to coast up fast and then hit the brakes.
It took only an hour or so on city streets for me to become accustomed to one-pedal driving and very soon I was able, by just feathering pressure on the accelerator pedal, to control acceleration, steady state, and deceleration until the last 5mph when I have to use the brake pedal. After a year or so I became so accustomed to one-pedal driving that when I had to use DW's Lexus and I let my foot off the gas it felt like a runaway acceleration event.
yeahsci
Member
It took me about a day to get used to feathering the accelerator. Then another day or so of trying not to constantly light up the brake lights by taking my foot off the accelerator too much. I manage to drive almost exclusively without touching the brake, except for the last <5mph when coming to a stop--the regen seems to almost fully release right before stopping.
