Aerodynamics come into play at higher speeds but at low speeds it's not as important.
I had fun playing with this tool http://www.wallaceracing.com/Calculate%20HP%20For%20Speed.php I plugged in some street speeds and frontal area makes a really big difference over 40MPH. sean On Thu, Nov 12, 2015 at 3:23 PM, EVDL Administrator via EV < ev@lists.evdl.org> wrote: > On 12 Nov 2015 at 11:59, Ing. Marco Antonio Gaxiola via EV wrote: > > > Considering the rule of EVs efficiency of 250Watt-hr per mile on a 2500 > lbs > > compact car, May it apply same in order to calculate the energy > efficiency of > > a prototype motorcycle? > > Maybe, but remember that a bike's aerodynamic qualities are significantly > worse than a car's. This is because the bike's rider adds quite a bit of > wind resistance. > > Another (possibly better) way to estimate the EV bike's energy efficiency > might be to look at a similar ICE bike's fuel efficiency. > > Taking the efficiency difference into account, an 8kWh lithium battery, > fully discharged, provides about the same range as a gallon of gasoline. > So > if your car got 35mpg as an ICEV, it should get around 230Wh/mi as an EV. > If your motorcycle got 100mpg as an ICEV, it should use around 80 Wh/mi as > an EV. > > Another way is to check the EV Album for similar vehicles. For example: > > http://evalbum.com/5125 > > This is a 450lb conversion bike with an 84v, 30ah (2520Wh) LiFePO4 battery. > The range is listed as 40mi, so that's 63 Wh/mi. > > Or this one: > > http://evalbum.com/5128 > > This has a 768Wh battery and a range of 15 miles for an energy usage of > 51.2 > Wh/mi. However, the top speed is only 35mph, so the bikes' relatively poor > aerodynamics may not play a very large role here. > > This bike can do 60mph: > > http://evalbum.com/5114 > > Even though it weighs only 176lb, it has a 3990 (!) Wh battery and a range > of 50 miles, which works out to about 80 Wh/mi. > > David Roden - Akron, Ohio, USA > EVDL Administrator > > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > EVDL Information: http://www.evdl.org/help/ > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > Note: mail sent to "evpost" and "etpost" addresses will not > reach me. To send a private message, please obtain my > email address from the webpage http://www.evdl.org/help/ . > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Read EVAngel's EV News at http://evdl.org/evln/ > Please discuss EV drag racing at NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -- Sean Korb spk...@spkorb.org http://www.spkorb.org '65,'68 Mustangs,'68 Cougar,'78 R100/7,'60 Metro,'59 A35,'71 Pantera #1382 "The more you drive, the less intelligent you get" --Miller "Computers are useless. They can only give you answers." -P. Picasso -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20151113/b44013cd/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
