Electric bike generator?

I have an electric bike that has a 24 volt 450 watt motor, running on the back wheel.  would it be possible to fit a front hub motor  on the front wheel to ether help with charging the battery's while using the electric motor to run the bike or be able to power the motor when you have started to move.  If this is possible what size hub motor would I need in the front wheel and what modification would I have to make.

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Kiteman8 months ago

No, and yes.

If you want to charge the battery while the motor is running, then no. That's a perpetual motion machine, they can't work.

If you want to top up the battery as you pedal, then yes, it could work.

If you are wanting to extend the life of a charge, look into regenerative braking, which puts energy back into the battery whenever you use the brakes.

In that case better attach the generator to the pedal rather than the front wheel where it will be a load on the drive all the time.

iceng rickharris8 months ago


A very astute, from an in-depth understanding of electrical vehicles..

iceng8 months ago

Great Byzantine Electrical Conceptualization. That electric bike can regenerate on its own going down hill or pedaling with the wind at your back.

I knew a young inventor that made a battery driven small buggy car and he was displeased about a 4 block range. So he added four specially modified alternators to work as low speed generators on each wheel to charge his battery.

Another GBEC actually constructed. To his dismay, starting with a charged battery, his new range was under one block !!

What happened each alternator uses wheel rotating energy and acts like a brake on each wheel but the generators do not make as much electrical power as the it takes to drive them and not only do not replenish the energy to drive them but deliver back much less energy because of efficiency loses in mechanical to electrical conversion and the mechanical wheel shaft energy to modified alternator shaft efficiency loses amount to an overall extra heavy load on the buggy..

seandogue iceng8 months ago

regenerative tech is used on trains and has been for quite a while. The idea is to engage the parasitic systems only when it makes sense, ie, slowing down or going downhill, when one can suckle frfeely from the teet of gravity.

rickharris iceng8 months ago

Iceng is saying no!

Sadly you will use energy driving the generators.