Regenerative Braking: beginners explanation, please

[SpikySimonW]

Please explain it to me like I’ve never owned an EV before!

I understand the one-pedal driving concept. Seems like a good idea but not one for me, at least not yet anyway.

I also get the mechanics behind regenerative braking, it’s more the selecting of 1/2/3/A that I’m asking about. Is this not simply various levels of aggressiveness towards one-pedal driving, but of course still having to use the brake pedal as doesn’t stop completely?

I suppose my question is: is it entirely driver preference (of the operation and interplay between accelerator and brake pedals), or is there an efficiency gain/loss depending on selection? As in, will similar energy recovery still occur on depressing the brake pedal - my understanding being the car still initially decelerates using the motors (akin to ramping up the “engine braking”) before applying the actual brakes - or would I be losing out on efficiency by sticking to driving slightly more old school?

TIA

 

[MG Clive]

Hello @SpikySimonW, I think you've already answered your own question really, but very simply:

Level 1 will slow you down a little bit, and put a small amount of energy back into the battery.
Level 2 will slow you down a bit more, and put a bit more energy back into the battery.
Level 3 will slow you down quite aggressively, and put even more energy back into the battery.
OPD will slow you down the quickest, and put the most energy back into the battery, while bringing you to a complete stop.

And yes, it's entirely the preference of the driver, and how it 'feels' to them when they're driving.

The car's actual brakes will hardly be used at all if you're only using the regenerative braking.

 

[mg4mc]

It should be said the levels only apply to lifting the accelerator. The first gentle part of the brake application will then increase the regen up to it's maximum before the friction brakes start being applied when the requested braking force becomes too much for regen to satisfy.

So you can use level 1, but still use the full amount of regen using the brake - you get a feel for it after a while, glancing at the regen figure helps at first.

 

[SpikySimonW]

Thanks both, very helpful to further/cement my understanding.

Suppose I might try level 3 and see how I get on, following the rationale it could maximise the amount of regenerative braking if I then get used to not using the friction brakes as much.

Though, probably better to stop overthinking it and just enjoy the car!

 

[decrep]

Suppose I might try level 3 and see how I get on, following the rationale it could maximise the amount of regenerative braking if I then get used to not using the friction brakes as much.

I think you've misunderstood.
Regen levels, don't really affect the regen/friction braking ratio.
Regen levels only adjust, the accelerator/brake pedal action.
at level 1 lifting off the go pedal, gives a regen level equivalent to ICE engine braking, then transfers regen request to the brake pedal.
As already mentioned the brake pedal has two functions. the first part of the travel invokes regen, the 2nd part of the travel applies the friction brakes.

So this all about driver feel, not about the amount of regen.

If you want an ICE car feel go for level 1, if you like just using 1 pedal to control speed, go with 3 or OPD. Not sure about level 2, you'll have to experiment and see what suits you best.