I know on an E Bike the time spent braking is almost nil. You naturally conserve you effort by coasting as much as possible and trying to hit lights on a roll. Using brakes is a great disappointment. The same is true for downhill runs - you mostly want to go as fast as you can, regen would counter that - a lot. I am in the camp that regen is an expensive waste of $ on an human powered, electric assist vehicle.
When I am driving a car, it is not that different. I mostly try not to rush ahead only to stop quickly, and sometimes I can make my commute with almost no braking. That total time on a 40 minute drive - couldn't be more than 5 minutes. If I am right, that is 12.5% of time. The inefficiency would then take half that away My estimate of braking time is probably quite high, but I don't know how much. I would guess no more than 6% return from regen. On Mon, Mar 17, 2014 at 2:03 PM, Peri Hartman <[email protected]> wrote: > Tom, thanks for the info. > > I'm not sure what you mean in your 2500' climb: first you say regen put > back > about 24% of the energy and then you say that (or something) was about 1/2 > the potential energy. Are you saying that the regen recouped about 24% of > the energy expended in that scenario? > > I hope my regen is better than 10% in city driving. In your second example > you include some higher speed segments which would add a lot of wind > resistance. My speeds are normally below 30mph. > > Peri > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf > Of tomw > Sent: 17 March, 2014 8:16 AM > To: [email protected] > Subject: Re: [EVDL] How can regen be a reason to buy or not? : EVLN: Fiat > 500e EV> close to perfect > > "/I'll "second" that regen is important. Another example is city driving. > If > you have a lot of hills and stop & go every few blocks, regen can add a lot > of range, even if it's only 70 or 80% efficient. > > I don't have an obvious way to measure this. Has anyone else done so?/" > > I've posted data from my car on diyelectricar a number of times over the > last 4 years. I data logged battery I, V, Ah with a TBS gauge, and vehicle > miles, elevation and speed with a GPS. Doesn't seem to affect anyone > though. > As Lakoff, cognitive scientist, says "If the facts don't fit the frame, the > facts are rejected." > > My data indicates that around half of my car's kinetic energy goes into > potential energy in the batteries when stopping. Going down a 9 mile long > hill, around 2500 ft elevation change, the energy into the batteries by > regen was about 24% of what it took to drive up, and about half of the > vehicle's potential energy at the top. On a short drive for a video, where > I drove about 100 yards at 25 mph, stopped at a stop sign, turned left and > drove about 1/4 mile at max 45 mph, turned right onto a freeway on ramp, > accelerated onto the freeway and drove about 2 miles with max 70 mph speed, > exited, stopped, turned right, drove about 1/4 mile, turned right and drove > about 1/2 mile at 35 mph, regen was 10% of the energy used. I've also > measured around 10% on other, longer local trips. > > Summary of some posts here: > http://www.diyelectriccar.com/forums/showpost.php?p=366384&postcount=20 > Would have posted here but can't do graphs/figures here. > > > > -- > View this message in context: > > http://electric-vehicle-discussion-list.413529.n4.nabble.com/EVLN-Fiat-500e- > EV-close-to-perfect-tp4668392p4668489.html > Sent from the Electric Vehicle Discussion List mailing list archive at > Nabble.com. > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA > (http://groups.yahoo.com/group/NEDRA) > > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, "The summer day." To invent, you need a good imagination and a pile of junk. Thomas A. Edison<http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell (919) 513-0418 Desk [email protected] <[email protected]> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140317/c562db1d/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
