GuyD
Posts: 32
Joined: Wed Jun 06, 2018 6:06 am

Re: Regen and creep operation?!

Thu Dec 12, 2019 9:56 am

CanisLupus wrote:
Thu Dec 12, 2019 7:57 am
Just a thought , could there be an issue with the pedal position sensing mechanism and/or electronics ?
Hi, That's exactly what I'm thinking...…

Today the creep came and went (all this is on smooth roads at low speeds and in a straight line!) It is very slight and not an issue as such but it is occasionally disconcerting to have the car not slow on lift-off or creep slowly towards the car in front (on the level!) - especially when I am expecting it to be sitting stationary...…..

Funnily Tesla introduced "Creep' for the Model S to accommodate USA drivers who were used to automatics - sad but true. And our absolute favourite EV feature is regen so going back to having to brake (like a primitive ICE car) in traffic is a bummer. Indeed I'd like far stronger regen - I read that the 64Ahr i3's had stronger regen and new-to-EV drivers found it made driving jerky so they moved a bit of the regen across to the brake pedal in the 94Ahr model. Can anyone confirm if this is true - certainly the demo 64Ahr i3 we test drove seemed to have more regen.....

GuyD
Posts: 32
Joined: Wed Jun 06, 2018 6:06 am

Re: Regen and creep operation?!

Thu Dec 12, 2019 9:58 am

CanisLupus wrote:
Thu Dec 12, 2019 7:57 am
Just a thought , could there be an issue with the pedal position sensing mechanism and/or electronics ?
Hi, That's exactly what I'm thinking...…

Today the creep came and went (all this is on smooth roads at low speeds and in a straight line!) It is very slight and not an issue as such but it is occasionally disconcerting to have the car not slow on lift-off or creep slowly towards the car in front (on the level!) - especially when I am expecting it to be sitting stationary...…..

Funnily Tesla introduced "Creep' for the Model S to accommodate USA drivers who were used to automatics - sad but true. And our absolute favourite EV feature is regen so going back to having to brake (like a primitive ICE car) in traffic is a bummer. Indeed I'd like far stronger regen - I read that the 64Ahr i3's had stronger regen and new-to-EV drivers found it made driving jerky so they moved a bit of the regen across to the brake pedal in the 94Ahr model. Can anyone confirm if this is true - certainly the demo 64Ahr i3 we test drove seemed to have more regen.....

GuyD
Posts: 32
Joined: Wed Jun 06, 2018 6:06 am

Re: Regen and creep operation?!

Thu Dec 12, 2019 9:59 am

Sorry about the double posting - dunno how that happened!

CanisLupus
Posts: 121
Joined: Thu Sep 15, 2016 10:48 pm

Re: Regen and creep operation?!

Fri Dec 13, 2019 9:45 am

Remember that the 'Hill Hold' function will keep the i3 from rolling backwards when stopped on an uphill (unless the hill is too steep) but when stopped on a down hill of any grade the i3 will indeed creep forward unless the brake is engaged to the friction level .

jadnashuanh
Posts: 5196
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Regen and creep operation?!

Fri Dec 13, 2019 5:26 pm

The hold function prevents the car from moving in the opposite direction of the 'gear' selector, so also works in reverse.

In some places in the world, it's considered bad (and rude) practice, to sit at a stop or light with your brake applied. They use their parking brake. If you haven't tried it, on the i3, as long as you've got your seat belt on, the car WILL automatically release the parking brake when you touch the go pedal. If you're one of those that don't wear your belt, you'd have to manually turn the brake off which also requires you to first push on the brake pedal.

I find that very convenient. WHat I miss that's on my other BMW, is a setting called automatic hold. That automatically applies the parking brake once you are fully stopped, and releases it when you hit the gas pedal. No worry about creeping as long as you don't accidentally hit the gas pedal. I'd like it even better if I didn't have to turn it on each time, as it defaults to off.
Jim DeBruycker
2014 i3 BEV, 2021 X5 45e
(The i3 will be sold soon, <17K-miles, interested?)

3pete
Posts: 121
Joined: Tue Mar 19, 2019 9:03 pm

Re: Regen and creep operation?!

Sat Dec 14, 2019 10:44 pm

jadnashuanh wrote:
Fri Dec 13, 2019 5:26 pm
In some places in the world, it's considered bad (and rude) practice, to sit at a stop or light with your brake applied. They use their parking brake.
I'm curious about this:
Where are these places?
Why do people care what method you use to be "stopped at a red light"? / Why is the brake "rude"?
Why is the parking brake preferred (do these places have a large star-gazing community and dislike the excess light pollution from brake lights of cars stopped at an intersection)?
What if you get rear ended?

#so_many_questions

eNate
Posts: 663
Joined: Mon Sep 09, 2019 5:33 pm

Re: Regen and creep operation?!

Sat Dec 14, 2019 11:10 pm

3pete wrote:
Sat Dec 14, 2019 10:44 pm
jadnashuanh wrote:
Fri Dec 13, 2019 5:26 pm
In some places in the world, it's considered bad (and rude) practice, to sit at a stop or light with your brake applied. They use their parking brake.
I'm curious about this:
Where are these places?
Why do people care what method you use to be "stopped at a red light"? / Why is the brake "rude"?
Why is the parking brake preferred (do these places have a large star-gazing community and dislike the excess light pollution from brake lights of cars stopped at an intersection)?
What if you get rear ended?

#so_many_questions
I've heard this applied to Britain. I don't know how true or widely adopted it's followed, just forum posts.

Some cars put out a blindly bright amount of brake light. So I can see how it might be interpreted as inconsiderate to blind the occupants of the car that stops behind you at a long stoplight, particularly out in an area away from bright city lights. With the automatically disengaging parking brakes that are showing up in many cars, it would be pretty easy to adopt this technique. I don't suppose you would do it if a car wasn't stopped behind you, to address your rear ender concern.

I can't recall ever being stopped behind an i3 at night at a dark intersection. Are our brake lights particularly bright?
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jadnashuanh
Posts: 5196
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Regen and creep operation?!

Sat Dec 14, 2019 11:38 pm

It was a member from the UK that mentioned the thing about the parking brake at a stop. Especially with the advent of the third, high center brake light long ago now, you can have a pretty bright lamp shining in your eyes. SOme brake lights are higher than others, too, and that can make a difference. Many places outside of the US still are driving a lot of compact cars, so they tend to be lower, and sometimes, a bigger one can really be in your face.

This also probably comes from the manual transmission...using the parking brake is much more common at a stop to ensure you're not going to coast when you release the brake to then get onto the clutch. Those habits tend to carry over. All of my early cars had a manual transmission, so it became a habit for me to use the parking brake at a stop. Over 60-years, I've not had someone fail to notice my car and fail to stop. I've been hit by an idiot that thought he could brake at the last moment on glare ice, but that's a different issue altogether.

I think it also helps to ensure that the emergency brake cable stays free rather than getting gunked up, then sticking if it isn't used regularly.

If you've got some idiot steaming up behind you while stopped at a light and oblivious to your presence, you could always hit the brakes. I've done that a few times, but that also means you have to be paying attention yourself! Most of the time, the running lights are on, so even during the day, there are some lights on back there. The more likely problem is some idiot, during poor traction conditions, is just too close and going too fast and brake lights or not, they'd end up hitting you. If you've got room to move, try to move out of their way without getting broadsided yourself in the process!
Jim DeBruycker
2014 i3 BEV, 2021 X5 45e
(The i3 will be sold soon, <17K-miles, interested?)

3pete
Posts: 121
Joined: Tue Mar 19, 2019 9:03 pm

Re: Regen and creep operation?!

Sun Dec 15, 2019 3:25 pm

Ah, that makes sense. The only time I've been blinded by anyone's brake lights was when the plastic was broken off and it was the bare, white bulb shining directly into my eyes.

When driving a manual, I try to make a point of pressing the brake if no one is stopped behind me just as an added indication that I'm stopped there even if it's not required by the incline of the street. If someone's behind me, I'm definitely more likely to take my foot off the brake and just sit on flat ground but I can't remember the last time I used the parking brake to hold at an intersection.

On the other hand, in the i3 I sometimes use the e-brake for the novelty.

eNate
Posts: 663
Joined: Mon Sep 09, 2019 5:33 pm

Re: Regen and creep operation?!

Sun Dec 15, 2019 4:49 pm

One thing I'd be curious about is the longevity of the parking brake motor. If the i3 is anything like my last car, there's a small motor on each rear caliper that screws the pads down to a clamped position, and I can hear the motor "wind up" a bit as the torque builds to achieve holding force.

If that gets used with as much greater frequency as this technique entails, is that asking for early trouble?

As an alternative, I'm imagining a system that requires the driver to apply the necessary system pressure at the brake pedal, then closing an in-line solenoid to hold that pressure. But that introduces a new complexity in the brake line that might cause air leaks, fluid leaks, or who know what. So nevermind? :D
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