I think you will need closer to 80-100 ahr of those batteries to get 50 miles. With a 100 ahr pack of Nicads at 48 volts I had a 35 to 40 mile range at 50 mph. The pack weighed 230 lbs. Your lithiums will be quite a bit lighter and since you are running at 72 volts instead of 48 you would have 50% more overall capacity than I did. Weight however is not much of a factor once you get up to cruising speed. Once you get up to speed it is mostly aeordynamics, and this is one factor where all motorcycles suck. With only a 50 ahr pack you are hoping to do 1 mile per ahr which I think is a bit over optimistic except for at very low speeds. You should compare notes with some of the other 72 volt motorcycles and see how many ahrs per mile they get. I know at 48 volts I average 2.5 - 3 ahr per mile. damon
> Date: Tue, 6 May 2008 16:13:07 -0700> From: [EMAIL PROTECTED]> To: > listserv@electricmotorcycles.net> Subject: [ElectricMotorcycles] Before we > proceed on the conversion...> > Hello again,> > Thanks for all the advice on > bikes and weights. The bike we settled on was a 250cc 89 Ninja. ((This was a > bit of a compromise, as we'd have preferred a 200 lb ICE> bike instead of a > 300 lb one).> > Our goal again, is to do an ev-conversion with 50 mph top > speed and a 40-50 mile range. Doing this project with a like-minded partner, > we've expanded our budget, so Lithium looks like the best bet.> > We'd like > to get your advice on this configuration:> > Batteries: > 72V, 50AH LFP pack > w/BMS from Hipower> > Controller+Motor kit which contains:> E-tek-RT Motor, > Alltrax AXE 7234> [I know there were some negatives regarding the older > version of Etek, but what about this one?]> > Info about batteries:> > > http://www.chinabatteries.net/www/en/prod.htm> > weight is 92 lbs, >1000 > cycles> (>2000 cycles under optimal discharge conditions according to > manufacturer.)> > Some numbers:> > WH/lb = 39.13> [Compare w/ 16.4 WH/lb for > an equivalent SLA system using B&B batteries]> > approx cost: $2650 for a > 24-cell pack, $3500 incl BMS.> > Cost/KWH = $730 excl BMS> Cost/KWH/cycle = > $0.73 assuming 1000 cycles> Cost/KWH/cycle = $0.37 assuming 2000 cycles> > [Compare with $0.61 for an equivalent SLA system using B&B batteries, > assuming 500 cycles]> > Total estimated cost (incl bike): $5500. Again > sharing the bike with a friend helps ease the bite on the wallet.> > Thanks,> > Sri Subramanian> Roy Prince> _________________________________________________________________ Stay in touch when you're away with Windows Live Messenger. http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_Refresh_messenger_052008
