Bicycle generator to charge your phone

August 13, 2026, 09:58:15 AM

I talk to a lot of people about designing and building generators. One of the first things they usually ask is; “can you build one to charge my phone with a bicycle?”. It seems like a lot of people are interested in that.

So, I decided to build one and post it here so people that are interested can build one themselves.

I am building this little bicycle generator to test it in many ways and collect data. This will be a prototype.

Ultimately, what I want to do is design and build a generator that is optimized specifically to be powered by a regular average bicycle without making any modifications the bicycle. After all, not many people would like to have a bicycle just to run the generator, they would want to be able to ride the bike too.

After I run the tests and collect data, my plan is to design a generator that could be used in an emergency during a power failure. I want this bicycle generator to be able to charge phones quickly, and also to have enough power to run many low power devices that run on 12 volts.

Here are some of the parts that I will be using for this prototype.

I’ll try to get more done this weekend.

Ed

Re: Bicycle generator to charge your phone

Reply #1 – August 15, 2026, 08:30:44 PM

I was able to do more work on the generator today.
Here are pictures of the coil spools and the rotor and magnets.

Here is the generator, I assemble it to test the fitting of the parts.

I also got the coil winder ready to go.

Now all I need is find the time to wind the coils and build the stator.

Ed

Re: Bicycle generator to charge your phone

Reply #2 – August 17, 2026, 10:19:42 PM

Watching with interest.
I remember having a wheel-rim dynamo for my bike when I was a kid. It kept a headlight lit, barely, and only while moving forward.