Lee, what about hosting your spreadsheets at your website, along with
all the other technical information?
-Chris
On 5/18/2015 5:17 PM, Lee Hart via EV wrote:
Paul Dove wrote:
When I built mine I did a spread sheet.
Ben Goren via EV wrote:
Any chance you have a copy handy and would be willing to share?
Here is a copy of the Excel spreadsheet I use for my performance
calculations. This is a "dead" version for email purposes (filled out
for my 1980 LeCar / Lectric Leopard EV), but it shows the equations
for the calculations. Ben, I can send a "live" version to your email
address if you like (let me know off-list).
Renault LeCar HP vs. Speed Calculations by: Lee Hart
HP = rolling resistance + power train loss + aerodynamic drag
where rolling resistance = R W V / 375
R = tire roll resistance 0.008
W = vehicle weight, lbs. 2306
V = velocity, mph 5
power train loss = C W V^2 / 375
C = loss coefficient 0.0002
I^2R, gear, bearing, stirring etc.
aerodynamic drag = Cd A V^3 / 146,625
Cd = drag coefficient 0.35
A = frontal area, sq.ft. 18
motor ADC L91 15 HP at 96 volts and 135 amps = 86% efficiency
batteries 12 Concorde 12 v each weight (lbs) 63
33% of curb wt 144 v total amp-hrs (20-hr rate) 95
175 minutes at 25 amps Peukert amp-hrs 104
621 minutes at 8 amps Peukert exponent 1.11
MPH 25 30 35 40 45 50 55 60
MotorHP 2.67 3.74 5.07 6.69 8.62 10.91 13.57 16.66
Eff. 66% 72% 77% 81% 84% 85% 86% 86%
WattsIn 3039 3863 4892 6160 7701 9554 11762 14373
Amps 22 28 36 45 56 70 86 105
Minutes 200 153 118 91 71 56 45 36
Miles 83 77 69 61 54 47 41 36
A spreadsheet makes it easy to play "what if..." games. What if I add
a battery? What if I change from lead-acid to lithium? What if I
reduce the weight, or improve aerodynamics, etc.
_______________________________________________
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)
