Your System's Power Density

What's your favorite e-ride's power density expressed as Watts/Kg, including peak motor efficiency and total rider + bike weight? (including batteries, motor, etc)

If unsure of peak efficiency, use 90% for brushless systems, and 80% for brushed.

Results should create a distribution curve we can later compare to acceleration times, or hill climbing grade @ speed results.
--------------------------------------------------------
For example, my x5:

80 volts X 35 amps = 2,800 watts.

2,800 watts X 90% peak efficiency = 2,520 watts

2,520 watts of Power to the pavement.

Bike weight = 45kg. My weight = 77kg. Total weight = 122 kg

System Power Density = 2,520 watts / 122 kg = 20.6 Watts/Kg

My Currie:

24V x 35A @80% eff. = 672W

bike:34kg + me:72kg = 106kg

6.3W/kg

:lol:

6.3 W/kg!!!

Cheese Whiz man, you're almost better off just pedaling a lighter, normal bike! Time to overvolt that lazy Currie! :wink:

http://www.northeastcycling.com/neclimbs_hillcalc.htm

xyster said:

6.3 W/kg!!!
Cheese Whiz man, you're almost better off just pedaling a lighter, normal bike! Time to overvolt that lazy Currie! :wink:

Click to expand...

Could be...

but the density rating doesn't account for how many batteries I have... I can go slow for a good while with 48AH. A high-eff outrunner will be even better.


8)

According to the formula, 16.94 which I rounded to 17 and submitted. Guess to bikes weight makes rounding fair.

Have NO CLUE as to what this means. My 5304 on a 26" wheel with 2.0 slicks to 70 lbs, with 4 12V 12 AH SLA batteries pulls my 220 pound body to 32 mph with no wind and a comfortable 12 - 13 miles at 20 - 22 mph but the watts up is telling me to slow down by then if I want to get home. I've never pushed the batteries to dead so can only assume I could get 20 miles if I actually slowed it down.

Mike

Bicycle: 39kg (all-up-weight) + Me: 73kg = Total: 112kg

Peak power: 47V@20A@90% eff. = 846W

Peak watts per kg = 7.55W/kg

Overall the bike's acceleration is a bit slow, but the peak speed is a nice 28mph and I can ride well over 20 miles between charging (with pedaling, but I always pedal). I've never drained the pack, but based on estimated capacity left and the drain rate, I bet I could ride around 30 miles before I'd drain the pack.

The bike & I = 99.1Kg
36v x 25a = 900watts
900w x 80% eff. = 720watts
720w / 99.1kg = 7.26w/kg

peak speed 35km/h. Can go about 10km and the sla's read 12.2v x 3
Never run at peak speed for very long 1 min. at most.

Eric

38kg trike, 78kg me, =116kg.
84v X 30A = 2520 @ 90%=2268 / 116 = 19.55 w/kg

Can't resist this one

Bike: 135 kg
Me: 65 kg
Peak power: 60V x 300A @ 86% eff. = 15,500W
Power density: 77.5 W/kg

Vego SX-600 plus me: 123 Kg.
Motor output power: 2,500W
Power density = 20.3 W/Kg

Lets see;

(36V X 20A) X 90% = 648W

34 Kg (bike) + 64 Kg (me) = 98 Kg total

648W / 98Kg = 6.61 W/Kg