NeilBlanchard wrote:Regenerative braking will ALWAYS regain LESS energy than you used getting the car up to speed. So, regen only can reduce the energy you use, so your range increases.
Coasting can decrease the energy you use even MORE than regen can - because coasting loses less energy.
Here's what I do: I coast when I need to carry speed, and only use regen when I need to slow down.
My winter average in our Leaf was 4.7 miles / kWh, and my summer average is 5.3 miles / kWh. Our e-Golf is quite similar, but it doesn't keep a long term average.
Coasting is 0% efficient
Try this test, speed up to 30mph, coast to a stop. Measure energy recovered by coasting. Answer is 0
Now speed up to 30mph and regen brake to a stop. Measure energy recovered by Regen braking. Answer > 0
Regen braking is about 80% efficient at turning kinetic and potential energy into chemical energy in your battery.
Try this test:
Speed up to 30 MPH, coast to a stop. Note energy consumed...it's the amount it took to get to 30 MPH plus zero, as you say, from coasting. But put a marker by the road where you stop. Note how long it took you to reach that point from the beginning of the test.
Go back to beginning. Speed up to 30 MPH, brake to a stop. Note energy consumed. It will be > 0 because regeneration is not 100% efficient. Now continue driving until you get the the flag, brake to a stop. Get there in the same time it took you in the first test
You will find that the energy consumed in the second case, to go the same distance in the same time is much higher than in the first case because energy is wasted into heat, both during regeneration and during the following acceleration.
Every time energy make a round trip into and out of the battery, some is lost to heat.