ebikes.ca simulator consumption off?

[itchynackers]

I've tried multiple combinations of setups I've used, and the ebikes.ca simulator http://ebikes.ca/simulator/ is always WAY too high on the consumption compared to actual usage. Anyone else have this problem, or am I just using it wrong?

You can see it is saying 62.2wh/mi which is almost twice the observed value.

 

[Alan B]

Do you get 37 mph at full throttle?

The bike calculator at:

http://www.mne.psu.edu/lamancusa/ProdDiss/Bicycle/bikecalc1.htm

Shows a worst case of 1187 watts for 37 mph whereas ebikes.ca shows 1820 watts in your example. This suggests the load is estimated too high, if the other calculator is right. It is based on published drag data from 1989.

Interesting.

 

[Alan B]

This calculator:

http://www.mne.psu.edu/lamancusa/ProdDiss/Bicycle/bikecalc1.htm

shows 1820 watts producing 39.67 mph

and 1200 watts producing 33.9 mph

with MTB type assumptions

 

[Alan B]

This calculator:

http://www.noping.net/english/

Shows:

1200 watts produces 32 mph

1800 watts produces 37 mph

which agrees with ebikes.ca

 

[itchynackers]

At 18a, i get roughly 37mph. The chart shows about 1800 watts to go 37mph.

So...if we go for 1 hour, then 1800watts/37mph = 48.6wh/mile

What is the ebikes consumption number stating? It seems way high.

 

[Alan B]

At 18a, i get roughly 37mph. The chart shows about 1800 watts to go 37mph.

So...if we go for 1 hour, then 1800watts/37mph = 48.6wh/mile

What is the ebikes consumption number stating? It seems way high.

1800 watts is motor output power. Battery power is much higher at 2300W due to efficiency losses in motor and controller.

 

[itchynackers]

So the cycle analyst reads motor power, not battery power?

 

[miuan]

Cycle analyst measures current drawn by controller from battery times voltage = INPUT power. It has no idea what torque and speed the motor produces and how much of this electricity is lost as heat.

 

[itchynackers]

Ok. I wonder why my CA consumption (battery) is significantly lower than the simulator (also battery) consumption. Just doesn't make sense to me. Oh well.

 

[Alan B]

The above example shows 8V sag due to 0.32 ohms battery resistance. This seems high and is one source of energy loss. How was this figure arrived at?

The controller in the above example is shown as a 25A controller, this might be a 6 FET which has more loss than a 12 FET that most folks use at 100 volts.

Calibration of speedometer is also important - differences in speed make quite a difference in efficiency. Also shunt calibration. A few amps of error makes a difference in the power used.

Altitude, air temperature, rider size, clothing and riding posture change the air drag. The simulator doesn't indicate what posture is in use, but that makes a significant difference at 37 mph.

Gradient is also important - a road that appears level may in fact be slightly downhill leading to error in the energy used.

Another difficulty is measuring steady state. Slight acceleration or deceleration is hard to detect and makes big differences in power used.

 

[Joe90]

My experience show that the latest simulator is damn close to real world.
at least for my configuration it predict within a few % my actual top speed and range considering speed.