Self Charging eBike

Marc V

Okay Electrical Engineers out talking to EEs and Physic guys, I always heard this type of stuff is not really perpetual since a system like this will be using more energy to produce. But it sounds like it will be an actual range extender?

Please reply in simple to understand terms, personally the actual science and critical details will go over my head hehe, but if you want to show your work, I'm sure others will be happy to see :) haha


Plus the additional weight and wind resistance of the bodies (bike + rider position) ;-)

The only viable option is regenerative braking, pretty complex on a pedelec (1) since your engine is not located where you break most (ie. the front wheel) and (2) it'd need to trigger as soon as you stop pedaling, before you activate the mechanical brakes, very uncomfortable.

Tesla Motors does it on the Model S and X, it's super-efficient as a brake when you released the accelerator and many drivers use it 90% of the time by coasting, except emergency ofc; super rare to change brake pads on a Tesla as a result.
Energy wise though, it only regens 3-5% of the battery max on a full trip and that's world-class hardware/software electrical engineers who shared offices with world-class rocket scientists at SpaceX.
It slowly became a non-critical selling point (not even mentioned on the current prospectus) like the 7-seats configuration.

These folks would probably be better off with a standard frame mount and that second battery they paid for as a back-up on a rack if max range is the objective.


Well-Known Member
Simple terms.

"Spinning the rear generator uses more energy from the bike's battery than it puts back into the spare battery"!

Marc V

Thanks for all the replies folks! I figured as much. My ebike is mostly a commuter eBike and I can make it into work and back home without pedaling on a full charge with a few miles to spare (I still charge the battery at work anyway). But was just curious what everyone thought about stuff like this.

I guess if I ever wanted to do long rides I would look into spare battery packs for now...

Marc V

I wonder how hard it is to pedal normally without using motor and just using generator to charge up battery. They say it is a low impact or resistance generator. I remember thinking it was cool when I used to power my head light with pedaling, but it did make for a hard ride, reminds me of the simpsons clip lol

But if it is still a smooth ride that might work for some, get some extra exercise and charge up the battery haha