Brakes activate regen?

[gwing]

Is the regen function linked to braking at all I wonder?

This morning I was looking closely at the Eco meter and noticed something interesting. Lifting foot off the accelerator causes regen to switch in and the vehicle to slow down as expected, however sometimes the regen isn't sufficient and you have to brake a bit as well. Now when you start braking the Eco meter goes further into regen than before and this seemed to be consistent behaviour and was particularly noticeable at slow speeds in stop/start traffic.

Unless I am imagining this I presume there is some internal logic that switches to full regen if the brakes are activated, which would seem to make sense from a design point of view.

If this is actually happening it sugests a change in driving habit to get the maximum mileage. Plainly it is best to anticipate ahead and ease off early enough to slow completely with regen if you can, however if you need to brake this implies you are better off lightly touching the brakes early (so as to switch in max regen for the longest possible period) rather than slowing under normal regen and then braking later.

Has anyone else noticed this?

[timpootle]

Now you mention it, yes I think it does behave like you say. I have no data to prove it either way, though.

[Flying John]

Yes its exactly right. At hi vehicle speed, lifting off throttle gives full regen. At lower speeds with no brake pedal action regen gets weaker , but if you then gently apply brake pedal pressure the regen increases again proportinally to the amoutn of brake you apply.

[gwing]

Thanks - I'm not completely imagining things then

I hadn't realised the low speed regen was proportional to brake pressure though. I guess it means that in slow speed traffic we should aim to brake as lightly as possible so as to minimise actual braking and maximise the regen.

I was rather hoping this was something we could use to effect at intermediate speeds, however after playing around a bit this morning that seems not to be the case. i.e. if travelling fast enough for regen to be automatically activated I couldn't see any extra regen being used when the brake pedal was lightly depressed.

[Flying John]

Thats right at high speed you just get all the regen it has to offer .

[gwing]

Thats right at high speed you just get all the regen it has to offer .

Even at quite low speeds, anything above about 10mph it seems. I think the manual quotes it somewhere but I don't have that in front of me, what was new (to me at least) was that even below the minimum regen speed regen is still activated with braking.

[ChrisB]

Yep all correct as John says.

At slow speed you can almost bring the vehicle to a stop on regen alone by feathering the brake pedal and not pressing it hard enough to actually bring the breaks

Yep the whole system works the same as yee olde Bedford CF Electric, eh John, nothing new or clever about it, the CF, from memory, even had a slightly different rod fitted into to the servo so the pedal throw was longer and thus the first 20% of pedal travel was all about regen before the Brakes came into play.


Just goes to show how little has changed and how well designed the Bedford was............ but then we knew that.

ChrisB

[Flying John]

Ah yes the good old CF - where are they now.

I often wonder if someone on the CF design team made their way to PSA - or perhaps they took one apart to get ideas. There are so many similarities with the CF that was 20 years ahead of its time - including the variable regen contolled by the brake pedal.

[EVan]

At low speeds (less than about 10mph), using the brake activates the, well, braking circuit. Above that speed it should be in full field regen anyway, so pressing the brake doesn't make any difference (you can check that with the amp reading on the evlite for example).