Introduction: Bicycle USB Output

Picture of Bicycle USB Output

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i use portable usb powerbanks for most of my projects (usb heated clothing, smart plant pot). and i also bike a lot. so i decided to create a very cheap, "clip on" power source to charge these batteries. it can then be used to charge a smartphone, tablet basically anything that needs a usb plug to recharge.


the goal is to reach 5V-500mA to charge these batteries. our design is using a dc motor found inside of an old all-in-one paper printer. the biggest one in there.. you could easily add another motor in parallel to boost the current. at 1-2amps we are now able to charge all new smartphones and tablets directly from the handle bar. but remember, we can easily, with a single motor, still charge a powerbank which then can charge any electronic device you may have.



when you apply power to a dc motor it starts to spin. and if you spin the shaft manually either by pedaling, gravity, water, wind etc. then your motor starts giving out electricity from the wires. i can easily generate upto 10-13V constantly while biking. you can implement the same idea in a different scenario such as a wind powered generator.!!


parts needed;

- dc motor

- female usb port

- boost/buck adjustable voltage regulator

- mini voltmeter (optional)

- powerbank

- frame (3D printed, DIY case)


let's get started..>

Step 1: Frame

Picture of Frame

i needed to design a clip on piece based off the dimensions of my bicycle. i used sketchup, a free VERY easy to use 3D design software. you can download and use the 3D printed frame i have designed -


or you can easily get creative with pipe holder clamps, nuts & bolts. any round object with some hot glue can be your wheel disk..


find a place on the front fork where you think it is safe to install the dc motor, and imagine a disk rubbing against the wheel attached on top.


also another housing was designed for the handle bars. this will house the voltage regulator, voltmeter and usb. you can easily use any tiny plastic container as housing.

Step 2: Adjust, Test, Wire

Picture of Adjust, Test, Wire

before we solder, let's do some tests


using a voltmeter check the polarity of the dc motor pins while the bicycle wheel is turning the forward moving direction. on your voltmeter screen a "- minus" will appear telling you that your polarity is reversed, simply change the wires around and now you will have the correct polarity.


find a 9V battery or any dc adapter that is higher than 5V. we now must set the output of the voltage meter as 5.1V. to do this simple attach a higher voltage power source as input and turning the little screw to see the voltmeter as 5.1V as output.


now we know the correct polarity of the dc motor with the correct direction, we are able to get a reading of voltage generated and our regulator is set at 5.1V. once you are sure everything is figured out, go ahead and solder all the wires for a permanent connection.


this step may be a bit confusing for beginners. ask questions in comments.
read; basic electronics, how to solder

Step 3: Conclusion

Picture of Conclusion

we are simply generating electricity from the motion of the bicycle moving. it is a very simple dc circuit.


the voltage regulator is pretty much taking care of all the work. keeping our unstable input voltage at a constantly set voltage output of 5.1V - which equals to enough power for charging a usb powerbank.!!


similar products are sold online for upto $50. you can make your own for under $5 and learn basic electronics, intro to 3D printing and design. go ahead give it a try..



second version will include a better motor mount, possibly by the back wheel and house 2 in parallel DC motors to be able to directly charge a smartphone. remember to like, share and follow.


Mase13 (author)2016-06-13

i went ahead and added a recitifier circuit. so i can go backwards.

Akin Yildiz (author)Mase132016-06-17

:) nice

BicycleBlueBook (author)2016-04-27

This is the most genius addition to a bike I've seen in a long time! For a list of other bicycle accessories that are must have check out BicycleBlueBook!

:) thank you for the kind words

Willy™ (author)2016-03-21

Tebrik ederim,güzel çalışma.

LucaU (author)2016-03-07

Hi, how did you make the shaft disc? My problem is how to connect a disc to the rotor.

Akin Yildiz (author)LucaU2016-03-07

hello LucaU,
the disc is printed as well, you will find it in the attached file. then it's just hot glued to the motor shaft. it fits perfectly on top of it. depending on the motor you find, the design might have to be adjusted however..

raskoe (author)2016-02-20

one problem if you turn your dynamo back

then there is a negative input voltage

is there any protection ?

Akin Yildiz (author)raskoe2016-03-01

i believe there is protection on the regulator module, if not a zener diode will work

Vishnu Menon (author)raskoe2016-02-24

just we can use a diode before the input feed(output power from motor)

greg.wilcher (author)2016-02-27

Could you do the same thing with an exercise bike

Akin Yildiz (author)greg.wilcher2016-02-28

yep, you don't actually have to be moving as long as you have a turning wheel it will work. so you can watch tv while charging your batteries :)
you should check these out;

ahmet_024102 (author)2016-02-27

hocam dinamo olarak 12 voltluk herhangi bir dc motor olur mu=

Akin Yildiz (author)ahmet_0241022016-02-27

evet, olur. motorun 12V olmasina gerek yok, daha dusuk yada buyuk olabilir, elektrik uretimi ona gore degisecek ama. daha cok volt, daga cok amperaj
question: will any 12V dc motor work.?
answer: yes it will. however you can use and size motor, smaller or larger. electricity generated will change due to size, more volts mean more amps

juntjoo (author)2016-02-12

This is cool and all but if money isn't an option, which is better, this or a dyno hub?

Akin Yildiz (author)juntjoo2016-02-12

dyno hub. this is just a proof of concept project. good thing about this is that you can find these motors anywhere for free. but you will need a lot of them to create enough current. they are best for making small wind, water powered phone chargers, good intro to electronics. dyno hubs are more efficient, powerful and designed for bikes specifically.

jeanniel1 (author)2016-02-11

Now that's really harnessing power efficiently. I'd often felt that bicyclists could power quite a few things, but didn't think about batteries... good one! Great 'ible.

Akin Yildiz (author)jeanniel12016-02-12

:) it is pretty cool to be able to plug in your phone with the map on the screen. you can take a very long bike ride and still not run out of battery

john.mckeown.73744 (author)2016-02-11

Very can run a few led's for night time safety off this as well..

yes very true. i think next i want to make a front headlight that just plugs into the usb. thank you for your interest.!

stannickel (author)2016-02-11

The basic idea is absolutely brilliant! Even if it is just for the fun of it.

Akin Yildiz (author)stannickel2016-02-11

it a great intro, especially for kids.. it does have a lot of potential in many ways. thank you for your interest.!

RichardW126 (author)2016-02-10

You might want to include a diode in line with the motor for reverse voltage. Normally you are always going forward on the bike but if for some reason you roll back on the bike the motor will produce reverse voltage for the buck converter and voltage meter. Unless they are self protected they could be damaged.

RichardW126 (author)RichardW1262016-02-10

Another idea would be to use a bridge rectifier in the circuit and you would get the correct polarity no matter which way the motor turns. A plus would be that the circuit would charge even if the bike was going backwards.

Akin Yildiz (author)RichardW1262016-02-10

yes very good point. i was just thinking about the same the thing the other day. it definitely turns backwards while transporting the bicycle.. thank you for noticing that

Dashing Rainbow Dash (author)2016-02-10

I have one of those brushless motors from a VCt. I shall make a rectifier for it and use that.i spun it with an LED on it and it lights up brightly with a good spin. I can't imagine what kind of power I'll get from it.

very nice, use a voltmeter and bicycle back wheel to test the voltage generated..

CFL_Browncoat (author)2016-02-09

You should absolutely enter this in an Instructables contest.

just did, please check back tomorrow to vote.!!


Nove216 (author)2016-02-09

I was thinking of doing this a while ago but I couldn't figure out how to mount the motor and I think I just my solution. thanks.

Akin Yildiz (author)Nove2162016-02-09

i chose the front side due to shorter wire usage. putting it on the back may be a long term better idea. it is almost impossible to do test with the front wheel. however on the back you could just pedal by hand at top speed and get very useful data. i need to that next. i'm guessing the amperage with dual motors is 600mA. it could be more when i'm at 10-13V input.
please share your work.!

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