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High regeneration vs Low

8148 Views 15 Replies 9 Participants Last post by  McRat
Seems to me that when highway driving (NOT city driving) it shouldn't make much difference which mode you're in. My (admittedly weak) grasp of physics tells me that if a certain mass has to be brought to a stop in a certain place, high regeneration will require power until close to the stopping point, then lots of regeneration will occur over a short time when the right foot lifts.

With low regeneration you take your foot of the "gas" earlier, so you have low regeneration but for a longer time. My guess is the result should be the same amount of juice fed back to the battery.

This argument assumes no use of the brakes, of course, until the stop is made. And it would not apply in stop and go traffic where you can't take time to anticipate a stop.

Anyone with a better scientific background care to comment?
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Not necessarily more scientific, but I've logged a lot of miles hypermiling.

First, we normally buy a nice car to enjoy it. So that comes first. Drive it the way that makes driving pleasant for you.

Now about hypermiling. The higher kW load you put on the electrics in either direction the more kWh is consumed as heat and the more cooling is used. A fast charge or discharge loses more power per mile. On paper it would seem blasting off from 0 to 50 mph then max regen back to 0 would cover distance at a faster average speed, hence save power, but I've seen the opposite. It's not huge like a gas car, but it's there.

So keeping the rate of acceleration and deceleration low improves range. For many drivers, it's easier to keep the regen peak down by using low regen augmented by the brake only if necessary. This also keeps you looking further ahead, so you decel earlier and accel more gradual.

The brake pedal regens at first, until you run out of regen capacity, then it uses the friction brakes. The friction brakes appear to always be in use at very low speed, say under 4 mph, so try to avoid complete stops.

Note: You will hear the exact opposite, and you will hear it doesn't make a difference. I base this on trying to achieve maximum miles per kWh in a car with a smaller battery that I can run empty since it has a gasoline generator should I run short. And when I tried to hypermile the I-Pace, I saw a similar effect, but I can't run it 'dry' too often.
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I'm not sure why they don't put a red LED on the dash that indicates automatic brake lights are coming on.

But yes, all the cars I know of currently made will turn on the brake lights when regen/ACC/AEB hits a certain deceleration level, this even applies to gas cars with ACC.
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