Speak EV - Electric Car Forums banner

1 - 10 of 10 Posts

·
Registered
Joined
·
409 Posts
Discussion Starter #1
Baffles me how my zoe (ze40) and i assume all others does adjust the speed while on cruise control by accelerating and regening instead of accelerating and coasting. It would of been considerably more economical if didnt regen unless for example the speed gone over by 2-3 mph ( downhill for example). Wish there was a way to disable regen on CC.
 

·
had an R240, got an R90, might get a ZE50
Joined
·
520 Posts
When going long distances on empty motorways I use eco and set the cruise speed to 75, which means it does 60 on the level and a bit less on uphill but no regen downhill unless it's a good downhill.
I wish there was more controllability on the Zoé.
 

·
Registered
Joined
·
233 Posts
You are setting a desired speed so the car tries to maintain just that. Cruise control on ICE cars would just use engine braking but now we have regen it just cuts in and does a better job of holding speed. Interesting workaround by the Bogieman, might have to give that a try.

Just one of those things that is set to be "ok" for all but not perfect for anyone.
Being able to turn off regen and coast would be great to start with and then when the speed creeps above a user changeable point, the regen came in would be a bit more sensible for me in most case but not all.
Same sort of argument as to why we can't adjust the regen amount anyway. I'd happily have it set to the max as I control the coast with the throttle anyway, one pedal driving would be nice.

Still better than the MG which uses the brakes to slow down when in cruise control. Unless that has been fixed recently.
 

·
Registered
Joined
·
2,342 Posts
My understanding is the MG system would need to be re-certified to use regen as part of the ACC. I think part of the reason for it using the system from an ICE is because it was already certified (braking force, response time, G level etc).

The MG does use regen for the speed limiter though.

But as someone else said, the reason EVs use regen to maintain speed is that they would speed up if coasting. The Honda E is an example of this - the regen is too weak, so it’ll exceed its set speed when going downhill.
 

·
Registered
Renault Zoe Intens 2013
Joined
·
269 Posts
didnt the ze20 have heavy regen when it first came out I hear , and no rear brake lights on with regen... but people didnt like it apparently , so Renault brought out an update for the ECU? - or am I dreaming?

I'd quite like it, any extra regen the better in my book. I wonder if theres a setting in DDT4all to change parameters for regen capacity? ;)

There is a section for uncoupled brakes I think I see I think, but maybe that for something else
 

·
Registered
Renault Zoe Intens 2013
Joined
·
269 Posts
What is the difference between regen and coasting then ? - I thought they both meant the same thing / the same outcome?
 

·
Registered
Joined
·
1,086 Posts
Coasting is where there is no regen and the car just free wheels without recovering energy. On motorways, some drivers think this is more economical than using regen, as the braking eff3ct from regen means you lose cruising speed and have to use energy to regain your speed.

in urban driving regen is more efficient as you have to brake and stop frequently.
 

·
Registered
Renault Zoe Intens 2013
Joined
·
269 Posts
ah right thanks - so you would be coasting and not regen'ing if say you had the gear shift in neutral then?
 

·
Registered
Joined
·
409 Posts
Discussion Starter #9
ah right thanks - so you would be coasting and not regen'ing if say you had the gear shift in neutral then?
if you feather accelerator or switch to N, you're effectively coasting.
Coasting is only more "economical" than regen if you can effectively coast without needing to hit the brakes.

  • In practical terms:
    If you're driving at 40mph and you regen from 100m before a set of lights to a stop, would be more economical to coast/neutral from 200-300m before to a stop without braking.

    If you're on Neutral and hit the brakes, there will be no regen, meaning you'd be better off on D and regen instead.
 

·
Registered
Joined
·
233 Posts
Main difference between regen and coasting is that regen will always have some losses in the energy conversion. If you coast then you are taking all of that out of the equation so although it doesn't gain any power back you aren't losing it in the first place.

Of course if you need to slow down at a rate greater than air/road resistance then regen is your friend and better than the ICE equivalent of throwing all that energy away as heat.
 
1 - 10 of 10 Posts
Top