my first bike was getting 140 watt/mile that was one etek at 48 volts 700 pounds total weight a mostly flat 20 mile trip [50% DOD] done in 45 minutes, stop and go traffic. however that is measured from the wall with a kill-o-watt. my new bike is still being broken in, but my last 20 mile trip [66% DOD] with two eteks 48 volts at 800 total pounds 45 mph average speed, stop and go, more hills, took 200 watt/mile. measured from the wall means charger loss and extra power put into the batteries. so a rough guess might be 75% of that amount? i think on-the-road watt/mile is good info, but i'm more interested in total power used
Garret Maki <[EMAIL PROTECTED]> wrote: Mark, 88whr/mile just seems lower than everyone else. Do you actually have instrumentation in place to count watt hours out of your pack or are you guessing based on what you think the SOC is? I have built several bikes with a current shunt and have used the emeter/Link 10 and also the cycle analyst to measure/ calculate actual whr/m and at 45 mph with a lighter bike I'm well over 100 with an etek and 300# bike and on a more similar bike to what you mention, around 117 whr/m with a series wound motor 50 psi in the tires and ducking behind the windshield with a fresh brake rebuild and new grease in the bearings. If you are using is cheap state of charge meter which is just a volt meter and going by the printed specs on the capacity of your batteries you are really just taking a poke in the dark about what the energy usage is and I'm afraid you'll be giving other builders false hope about what their range will be. I just want to keep it real here, and I don't think a lead bike converted from a gas bike will do better than 100 whr/mile avg. in 45 mph stop and go riding. Call me pessimistic, but I'd be happy to be proven wrong. I highly recommend this for $150 http://ebike.ca/drainbrain.shtml Garret, in Minneapolis now. Mark Eidson <[EMAIL PROTECTED]> wrote: I get 88whr per mile with my 72V bike. I have 6 PC1500 ~50aH AGM batteries. I figure about 30 miles to 80% DOD. The most I have driven is 24 miles to ~65% DOD. Typical speed is about 45MPH. I agree you will need more than 50aH. me On 5/6/08, damon henry wrote: > 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. IM anytime > you're online. --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. harry Albuquerque, NM http://www.austinev.org/evalbum/1179 http://geocities.com/solarcookingman --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.
