self charging ebike

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Venice Motor Bikes

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I found this picture on FB & thought it looked interesting, (& I'd share it with you).

I'm not sure if it's actually a good working design... It looks like a self charging ebike.
What do you ebike guys think? Could something like this really work??

My thoughts are that the alternator probably won't spin fast enough to keep it charged & also the battery is way too small.

What would you guys (with actual knowledge of ebikes) do to it?

ebike with alternator.jpg
 
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Tony01

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It looks like a setup with two electric motors for propulsion.

There is no “self charging e-bike”. That would be perpetual motion. Like plugging a power strip back into itself.
 

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Sidewinder Jerry

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The closest thing I've seen to a self charging ebike is it uses 2 hub motors and has 2 batteries. While one hub motor and battery is being used for propulsion the other hub motor is charging the other battery. Then when one battery gets low, it can be switched over to the other one.
 

Tony01

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The closest thing I've seen to a self charging ebike is it uses 2 hub motors and has 2 batteries. While one hub motor and battery is being used for propulsion the other hub motor is charging the other battery. Then when one battery gets low, it can be switched over to the other one.
Makes no sense at all. It’s physics 101: you spend energy to get moving and continue to move, then some of the energy is returned when you stop, ie heat in your brakes. Most e-bikes have regen braking of some sort which converts the kinetic energy of a moving bike into potential energy returned to the battery, TO SLOW DOWN instead of heating your rotors. You are talking about getting “free” energy from a moving bike however, it is not free and slows a bike down.
 

Sidewinder Jerry

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Makes no sense at all. It’s physics 101: you spend energy to get moving and continue to move, then some of the energy is returned when you stop, ie heat in your brakes. Most e-bikes have regen braking of some sort which converts the kinetic energy of a moving bike into potential energy returned to the battery, TO SLOW DOWN instead of heating your rotors. You are talking about getting “free” energy from a moving bike however, it is not free and slows a bike down.
Same thing hybrid cars do. While gas only is being used the electric motor acts as a generator to charge the battery.

While motor/battery A is being used/coasting, motor B is charging battery B. When battery A gets low it'll switch over to motor/battery B. Then motor A starts charging battery A while motor/battery B is being used/coasting.
 
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Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
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Los Angeles, CA.
It looks like a setup with two electric motors for propulsion.
This bike doesn't have two motors... it has an alternator over the tire (for charging) & a drive motor under the cranks.

I understand what you're saying about no such thing as perpetual motion motors... But a alternator does put out a solid 13.5 volts while running.
 

curtisfox

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This bike doesn't have two motors... it has an alternator over the tire (for charging) & a drive motor under the cranks.

I understand what you're saying about no such thing as perpetual motion motors... But a alternator does put out a solid 13.5 volts while running.
Yes it does, butt it also takes a lot of power to turn a alternator, especially if the battery is dead........Curt
 

Tony01

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Same thing hybrid cars do. While gas only is being used the electric motor acts as a generator to charge the battery.

While motor/battery A is being used/coasting, motor B is charging battery B. When battery A gets low it'll switch over to motor/battery B. Then motor A starts charging battery A while motor/battery B is being used/coasting.
That’s really not how it works and you need to read and try to understand my previous response, I can’t continue talking about this without repeating myself.

Electric motors are not 100% efficient, maybe 90% discharge and 30% on charge. So you will lose everything to efficiency anyway. A hybrid uses gas and regen braking to charge. You can’t use a battery and charge it at the same time- you’re either spending or charging.
 

Tony01

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This bike doesn't have two motors... it has an alternator over the tire (for charging) & a drive motor under the cranks.

I understand what you're saying about no such thing as perpetual motion motors... But a alternator does put out a solid 13.5 volts while running.
It doesn’t matter the type of motors… they’re both motors. My hub motor is a larger more efficient alternator. I either spend electricity or get 5% of it back. An alternator puts out energy at the cost of slowing you down.

ie go and take one and spin it. If it wouldn’t slow you down, theoretically it should continue to spin forever.
 

Sidewinder Jerry

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That’s really not how it works and you need to read and try to understand my previous response, I can’t continue talking about this without repeating myself.

Electric motors are not 100% efficient, maybe 90% discharge and 30% on charge. So you will lose everything to efficiency anyway. A hybrid uses gas and regen braking to charge. You can’t use a battery and charge it at the same time- you’re either spending or charging.
Nobody is talking about using and charging at the same time. In the hybrid car the engine is driving the motor to put charge back into the battery under gas power only. When electric motor is being used the engine shuts off.

The double hub motor double battery. You're correct in that depletion occurs much faster than charge. Not a perfect system but still extends range. This is why many prefer to stick with gas until much greater improvements are made in range, charge time, and vehicle cost.
 
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Tony01

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Nobody is talking about using and charging at the same time. In the hybrid car the engine is driving the motor to put charge back into the battery under gas power only. When electric motor is being used the engine shuts off.

The double hub motor double battery. You're correct in that depletion occurs much faster than charge. Not a perfect system but still extends range. This is why many prefer to stick with gas until much greater improvements are made in range, charge time, and vehicle cost.
No it does not extend range because you are saying trading electricity between two electric drive systems with the losses creates energy. Losses do not create energy.

A modern hybrid like the Prius uses two electric motors through a gear set to vary the ratio between the engine and wheels in a CVT type manner. It runs on gas at higher speeds and pure electric at slow speeds.
 
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Sidewinder Jerry

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Here's a video on the duel motor duel battery bicycle


What I was referring to about the engine driving the motor to recharge the battery was something I saw a view years back. I now see they've abandoned that idea and are using a second motor and even a third one as a generator




This may be our future as well.

 
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Tony01

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I’m sorry but just because there is a video of a dual hub ebike on the internet doesn’t make it true. You’re also using the “self charging” phrase with different meanings but comparing different videos named so as if they’re the same thing. They’re really not, and “self charging” is not allowed by the laws of nature unless you are describing how a hybrid battery gets charged by burning gasoline.
 

Sidewinder Jerry

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The thing is, I'm not saying any of these so called self-charging systems are perfected. Only they're closest systems that currently exist.

I'm pretty sure there was once a build on this forum which was a hybrid. It used 2 hub motors. The front hub was used as a generator only. Power to the rear hub came either from the battery or the front hub/generator when gas was being used. When the rear hub wasn't being used the front hub/generator or gravity put charge back into the battery.

Like I said none of these so called self-charging systems are perfect; which is why most of us prefer to stick with gas.
 
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