Regen Braking, Hard And Fast Or Slow And Long?

[cootuk]

Is there a best way to use regen braking coming up to a stop?

Say you were on a slight slope do you get more regen by braking as normal, or is it more if you feather the brake from further back?

Going downhill generally are people feathering the brake for regen, or just letting the car speed up naturally?

[Dave R.]

I've always assumed that, if I have the eco display up, then whilst the first segment is not fully lit, I'm just using regenerative braking. Once the segment is fully illuminated, then any additional braking will be using conventional (Friction) braking. Of course, though, once your speed is below some low value (can't remember what just now) then all braking is via the brakes.

So, for greatest efficiency, I guess the answer is to brake gently in order to use regen to bring the car down to a low speed, then, if you've timed it right, the car will naturally come to a halt due to friction... or you use the brakes for the last little bit of your deceleration.

Going downhill, if you feather the brakes (use the eco display to see how much regen is going... you want just under a full brick so that you don't start using the conventional brakes) then you will get the most out of regen. Of course, if the Battery is full, then you're just wasting energy!

It feels a bit odd riding the brakes going downhill (always been taught to use engine braking in the past)... but you should be OK provided you don't brake too hard & bring the friction brakes into play.

[Jan&tone]

From what i can remember of my gen2, Dave has it about right, gently does it is pretty much always best with a Prius, the gen3 is the same, gently, gently, catchee monkee....

[DrCez]

I agree with the above from Jan&Tone & Dave R. (is the correct term "+2"?)

I've read (on PriusChat) that gentler regen braking is considered to be more effective because there is a maximum rate at which the Battery can be charged and/or the recharging efficiency drops off as the charging current increases. I don't know how this relates to the "CHG" bar on the Gen 3 ECO (HSI) display (does the Gen 2 have something similar?): the HSI seems to imply that once the CHG area is full you'll bring in some friction braking, but doesn't indicate anything about charging efficiency varying according to position along the CHG bar.

Going downhill generally are people feathering the brake for regen, or just letting the car speed up naturally?

If it's safe (i.e. you won't end up going too fast and don't need to slow/stop after the hill) it's best not to use the brakes at all (there's always some energy loss in the conversion from momentum to Battery charge, so better to use momentum when possible), otherwise apply brakes gently from early on (better still try to avoid going too fast as you approach the top of the hill). Basically follow Jan&tone's mantra, even if you don't need to catch a monkee :)