For the sake of charging the battery, is it better to compress the braking zone or extend it? For instance if you are traveling 50 mph and you are 1000 feet from a stop sign, should you brake 500 feet out or 250 feet out for best energy recovery?

 

Start slowing down 2000 ft out, start applying the brake at 1000 lightly, try to avoid the stop completly by anticipating the next signal. then if you have to stop, you have wasted the least and recovered the most energy...you may **** a couple of people off, but some get it and follow you, it is interesting.... don't try on single lane roads at rush hour.

 

Good point: the best stop is the one you never have to make. But what if it was a stop sign and you had to make a full stop. Is it better to make it in a short period of time or a long one with respect to recovering the kinetic energy?

For the brake pads and rotors themselves, you're better off making the shorter stop. The least amount of contact time between the pad and the 800 degree rotor is best.

 

I just stop accelerating on my HAH which kicks in regen and starts slowing car down. I then apply brakes as I get closer to stopping point. Regen should work the same way on insight I would think.

 

I found a graph once where someone did a full stop from 50 over a bunch of difference distances and measured the energy returned to the pack. I can't find it now, but the moral of the story was to apply firm pressure to the pedal, but not any more.

 

No the long slow stops use the resistance of the hybrid system to slow the car and generate power, the long slow stop is far better for the brakes...when you apply the brakes lightly, they don't actually engage, that increases the regen and slows the car that way, once you are too slow for regen, the ice turns off and the friction brakes take over....on a quick stop, you are using far more of the friction braking and less of the regen even though the meter goes way into recharge....drive gently, the stop sign will still be there when you get to it.

 

As you press the brake harder the charging indicator goes up.
At some point the indicator is maxed out.

I would suspect that braking harder than that would not result in additional charging, it would just heat up the brake pads/disc.

 

Yes, but braking too much less than that increases losses due to friction from the road/wind/etc. I'm not saying that braking as slowly as possible isn't the way to go, since those road/wind losses would occur anyway while the ICE is running, but you can see how if you just measured the charge put in the battery, the sweet spot isn't the slowest brake possible.

 

"the moral of the story was to apply firm pressure to the pedal, but not any more"

I'd be inclined to agree, and would speculate that the Honda engineers would tailor regen efficiency to the typical driver and average brake pedal pressure.

Manuel Santos has suggested (either here or at CleanMPG) to increase brake pressure until the green bar's peak, no further. That is of course unless you have to stop sooner, then you do what you have to do

 

Well, I have a different priority than charging the battery.
In fact my goal is to use they "hybridness" of my hybrid as little as possible.

My priority is using as little gas to begin with by avoiding use of my brakes.
I try hard to NOT to get up to a speed that I'd need to brake down from.

I really think of braking as a little failure on my part.

Here's why:
A hybrid converts kinetic energy to electrical energy, stores it, then powers a moter to convert it back into kinetic energy via braking/regen. (ignoring wind and road friction which is a wash)
No system is perfect and I read that the hybrid system overall can only recover 30% of the kinetic energy.

That means a full 70% of your hybrid's kinetic energy is wasted.
I'd rather waste 0%.

If I was able to NEVER use my brakes I'd go farther on the gas that I used to get up to speed, and I would waste zero kinetic energy.
Once I GET going I try to KEEP going as far as possible - and use less gas by only get up to a minimum speed to begin with.
I've learned to gauge the distance in front of me and adjust my speed to minimize braking use.

I must be doing' something right.
My average MPG for the last 4 years of hybrid driving is over 60 MPG.