Pedals which drives a generator

Joined
Feb 26, 2018
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154
Do anyone know of any electric vehicles that comes with pedals which drives a generator that makes electricity for motor/battery?

Instead of a chain between the pedals and motor.

You could:
ride the vehicle without battery
ride to provide some of the electricity for the motor
charge the battery while the vehicle stands still

Something like this.
[youtube]gC9avH2GpnE[/youtube]
 
You need to furiously pedal for 30min in order to drive the electric motor for 3min.

 
I agree. Theory is nice because it helps the first prototype end up closer to the final version.

However, this has been done, and the results are as predicted.

If a motor gets warm, then some of the input energy is being converted to waste-heat, instead of work. This means that you have to input 250W in order for the motor to put out 200W of movement.
 
"You need to furiously pedal for 30min in order to drive the electric motor for 3min"

Could you post data to support that, please. It doesn't seem to align with the statement made about the 200 watts out can be had with 250 watts input.

Not trying to be confrontational, just would like to see the numbers applied to a real situation to learn.
Ie A person can pedal at 150 watts? for 30 minutes.
This will input x amount of watt hours into a 36 volt battery.
Then a 500 watt motor will use about x amount of energy in so much time on a flat road with no pedal assist cause the pedaling energy will be going to the generator.

I am just shocked that the efficiency is as bad as the 30 minutes in to 3 minutes out ratio stated?
 
Mikebike said:
"You need to furiously pedal for 30min in order to drive the electric motor for 3min"

Could you post data to support that, please. It doesn't seem to align with the statement made about the 200 watts out can be had with 250 watts input.

Not trying to be confrontational, just would like to see the numbers applied to a real situation to learn.
Ie A person can pedal at 150 watts? for 30 minutes.
This will input x amount of watt hours into a 36 volt battery.
Then a 500 watt motor will use x about of energy in so much time on a flat road with no pedal assist cause the pedaling energy will be going to the generator.

I am just shocked that the efficiency is as bad as the 30 minutes in to 3 minutes out ratio stated?

A very, very efficient system will have about 80% roundtrip efficiency (90% efficiency in, 90% efficiency out). This is comparable to sucky IGHs.
This is possible at certain range of powers, but will not be cheap or easy (or even possible) to maintain over wide range of speeds/powers.

I've been experimenting this those systems, I still have one installed to be used a bike trainer over the winter.
It is only viable in case routing transmission is VERY hard (say, velomobile) or even close to outright impossible (AWS/AWD velomobile with torque vectoring).

I think one of other better solutions (which I wanted to try, but the package with pedal hub got stolen and I could not even get the money back) is coaxial front hub cranks recumbent with overruning cranks...
At start and when climbing steep stuff at slow speed, you can pedal 'directly' with almost 100% efficiency (pedals driving the front hub 1:1, no chain). At high speed, hub is overruning the cranks and pedal generator takes over the pedalling load...

Ergonomic position, single speed chain run very high peak efficiency when you need it most (direct drive), cadence/load at your choice otherwise which is pretty cool.
 
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