First Time EV Buyers: Battery Size and Charging Apprehensions

[Riventures]

We deviated a bit too much on this discussion towards the end, but just to close it out with some final thoughts:

I took @OEVA ‘s advice, had a 50-amp circuit installed into the garage, and now charging is not even an afterthought. The car draws at of 8.8-8.9 kWh, and within less than 6 hours it charges from 25% to 80, and I have more than 200 miles of range. Generally it is less than 90 mins to go from low 60s to 80%.

in short, I was worried about nothing, this is even more convenient than a gas station now

Happy New Year everyone.

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[OEVA]

I think you are a little confused about how this works. Blended systems, as the name suggests, blend in friction braking during regen when the driver wants to slow down. It is in an independent system (like Tesla's) that the car adds in friction brakes on top of 100% regen. This is what happens if you take your foot off the skinny pedal (100% regen) and plant it on the wide one. Regen remains on.

So what would you call a system that applies only regen with the brake pedal until the driver calls for more "whoa" than is available from the electric motors and only then is friction braking added to make up the difference?
I don't know of any vehicles that use blended brakes as you define them. Can you identify some?

Blended braking systems do not always add a mix of friction and regen when depressing the brake pedal. They blend in friction brakes only as needed.
The advantage they hold for some that eschew a one pedal driving option is that using the brake pedal will always provide the amount of stopping power the driver requests. With systems like Tesla and apparently Rivian, lifting off the throttle can provide very low levels of whoa under some circumstances. If the battery is full and/or cold, usually very little regen is available. You've no doubt experienced this if you have ever charged your Tesla to 100% in preparation for a long trip.

I don't know of any vehicles that use blended brakes as you define them. Can you point me to some?

 

[Trekkie]

I don't know of any vehicles that use blended brakes as you define them. Can you point me to some?

Tesla as far as I know, only uses regen when you take foot off the accelerator, if you hit the brake pedal breaks engage and are 100% the reason the car is stopping. This is how its been explained to me, and at least judging by the brake dust all over my front wheels. I think I'm burning through brakes as fast as I did on gas cars.

I much prefer the method the german cars are using, where it's a mix like you described. When out of spec tested the Rivian on his short drive he thought they were using blended and was pleased with it compared to others if I remember right.

 

[SeaGeo]

Tesla as far as I know, only uses regen when you take foot off the accelerator, if you hit the brake pedal breaks engage and are 100% the reason the car is stopping. This is how its been explained to me, and at least judging by the brake dust all over my front wheels. I think I'm burning through brakes as fast as I did on gas cars.

I much prefer the method the german cars are using, where it's a mix like you described. When out of spec tested the Rivian on his short drive he thought they were using blended and was pleased with it compared to others if I remember right.

you have it backwards. The Rivian is mechanical breaking only with break pedal. Kyle was just really happy about the regen behavior and 1-pedal breaking (among other things).

 

[ajdelange]

Tesla as far as I know, only uses regen when you take foot off the accelerator, if you hit the brake pedal breaks engage and are 100% the reason the car is stopping. This is how its been explained to me, and at least judging by the brake dust all over my front wheels. You own an X and you think that the friction brakes do all the stopping if your foot is on the wide pedal? Next time you drive it look at the power meter when coming to a stop. You will see that regen is still being applied. It would be rather silly to shut it dowm when the friction brakes are being used as that would A)Waste battery and B)Increase friction brake wear rate.

I think I'm burning through brakes as fast as I did on gas cars.

Then you are not driving the car properly. You should seldom find your foot on the brake pedal and never during "normal" driving.

 

[ajdelange]

So what would you call a system that applies only regen with the brake pedal until the driver calls for more "whoa" than is available from the electric motors and only then is friction braking added to make up the difference?

I dunno. Whatever the marketing department tells me to call it. "Progressive"?

I don't know of any vehicles that use blended brakes as you define them. Can you identify some?

Tesla.

With systems like Tesla and apparently Rivian, lifting off the throttle can provide very low levels of whoa..

Evidently you have never driven a Tesla (or Rivian). Here's a plot of the deceleration from about 53 mph to a few mph using regen only.

I will allow that if you consider 0.1 - 0.2g "very low levels of whoa" that I can appreciate your POV but I don't think most people would consider those levels "very low" as they are about the levels that one would ask of a friction brake in coming to a traffic light or slowing down for a turn in any vehicle. Note that the vehicle is essentially stopped in 15 seconds. Also note that in Telsa's algorithm for scoring driver safety (to see if he is qualified to test FSD) points are deducted for any deceleration of > 0.2g.

... under some circumstances. If the battery is full and/or cold, usually very little regen is available. You've no doubt experienced this if you have ever charged your Tesla to 100% in preparation for a long trip.

If the battery is under stressful conditions the BMS does protect it by limiting regen. But the prudent driver does not operate his battery under stressful conditions. He does not charge it to 100% in preparation for long trips as today with the expansion of the SC network there is no need to. As for cold (which means < 50 °F), regen is limited to just under 50 kW (it may be limited further at colder temps but I have not personally experienced this) which easily handles most situations (like the one graphed) without limitation and the battery warms sufficiently after a few minutes of driving (would depend on how cold soaked it is) restoring full regen capacity. In practice I can do a 600 mile trip without ever touching the wide pedal (unless some idiot cuts me off on the freeway).

The reason I am going on about this at such length is that it's clear you don't understand these systems very well and it appears that your message to the readers is that regen braking, especially as implemented by Tesla and Rivian, is in the "bell and whistle" catagory i.e. pretty useless most or, at least, a large part of the time. Nothing could be further from the truth. I want the readers to understand that this is one of the best features of BEV vehicles and one that I think many will enjoy the most. I am sure you will be among those who do once you actually experience it, assuming, of course, that Rivian has done as good a job of implementing it as Tesla has done.

 

[ajdelange]

The Rivian is mechanical breaking only with break pedal.

I haven't (dammit) driven a Rivian yet so I can't say for sure but I doubt this as to shut off regen when using the friction brake is deployed doesn't make any sense. Tesla does NOT do that.

 

[SeaGeo]

I haven't (dammit) driven a Rivian yet so I can't say for sure but I doubt this as to shut off regen when using the friction brake is deployed doesn't make any sense. Tesla does NOT do that.

That's not what I was saying (or the person I was responding to if I understood them correctly).

In the R1T (and your tesla), if you take your foot totally off the accelerator, it applies full regen. Right? The "wide pedal" as you call it then adds mechanical braking on top of that.

On other cars, like the ID.4, liftoff applies either no, or some non-maximal amount of regen. Applying the break then increases regen until it maximizes it, and it then blends the braking in on top of that.

So in the R1T the brake pedal doesn't modulate regen like it does in say... the ID.4

 

[ajdelange]

In the R1T (and your tesla), if you take your foot totally off the accelerator, it applies full regen. Right? The "wide pedal" as you call it then adds mechanical breaking on top of that.

Right!

 

[r1t_kev]

Man if the grammar police ever find this thread, you guys are toast! Folks throwing "break" around like it means the same as "brake".

I'll see myself out.

 

[SeaGeo]

Man if the grammar police ever find this thread, you guys are toast! Folks throwing "break" around like it means the same as "brake".

I'll see myself out.

Lmao. Fail on my part. I'm going back to bed.

 

[gsqrd]

here,here...oops hear

 

[OEVA]

Evidently you have never driven a Tesla (or Rivian).

I've driven all Tesla models, including the original Roadster. I've driven them on road trips and have had early(ish) iterations of auto pilot scare the **** out of me with some pretty sketch actions.
I've drive almost every EV on the market for varying lengths, and owned several different brands. My experience allows me to speak from experience outside of a single model/brand

With systems like Tesla and apparently Rivian, lifting off the throttle can provide very low levels of whoa under some circumstances.

If you have to resort to distorting a post by not quoting the whole statement, it shows just how desperate you are to be "right" regardless of the facts:

The actual statement:

With systems like Tesla and apparently Rivian, lifting off the throttle can provide very low levels of whoa under some circumstances. If the battery is full and/or cold, usually very little regen is available.

I admit that my post was wrong. It should have read:
With systems like Tesla and apparently Rivian, any EV that uses a one pedal driving mode, or even significant amounts of regen mapped to the "skinny pedal", lifting off the throttle can provide very low levels of whoa under some circumstances. If the battery is full and/or cold, usually very little regen is available. This can catch the unsuspecting driver by surprise.


It is obvious you will not be convinced that any way other than the way Tesla does things has any advantages, and apparently see it as your mission to spread the word (according to Elon, even if it requires ignoring facts.

You can also find many people dedicated to the notion that the Earth is flat, The Holocaust was faked, Trump actually won, and other claims with no basis in fact.

True bended braking prioritizes regen when pressing the brake pedal and only adds in friction brakes if required. Not that hard a concept for most to wrap their head around.

 

[Craigins]

The "wide pedal" as you call it then adds mechanical braking on top of that.

Sadly this was not my experience at the test drive in Normal.

Not sure if they changed anything afterwards but the wide pedal disabled regen braking. Then when you let off the wide pedal regen braking kicked back in at full strength. It was quite jarring, I couldn't figure out why someone would implement it like that.

I couldn't move my foot fast enough from the wide to the skinny pedal without a sudden jerk of the full regen kicking back in.

 

[godfodder0901]

Sadly this was not my experience at the test drive in Normal.

Not sure if they changed anything afterwards but the wide pedal disabled regen braking. Then when you let off the wide pedal regen braking kicked back in at full strength. It was quite jarring, I couldn't figure out why someone would implement it like that.

I couldn't move my foot fast enough from the wide to the skinny pedal without a sudden jerk of the full regen kicking back in.

This is definitely not the experience I had during my test drive, so something must be different between at least two vehicles.

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