Introduction: Bike That Charges Your Cell Phone As You Ride!

Picture of Bike That Charges Your Cell Phone As You Ride!

My friend Jack and I wanted to make a bike that charges his cell phone as he rides, so we decided to use a small DC motor to power it!

For the peeps who don't know why it saves energy: 1st, you charge your phone without electricity from a power plant, obviously, because you are creating electricity by riding. 2nd, it gives you a reason to ride to wherever you want to go, reducing your carbon footprint drastically.

Note: the video is on the last step

Step 1: Get Your Parts!

Picture of Get Your Parts!

OK, so the parts list is pretty basic.

1 Bike that you are willing to do some stuff to (every thing is reversible)
1 Small gear that will fit into your chain
1 Small piece of wood
1 Smallish DC motor
1 Cell phone
1 Cell phone charger that you are willing to destroy
1 Solder
A crap load of duct tape
Hot glue
Assorted washers, nuts, and bolts

Soldering Iron
Socket wrench
Hot glue gun
Coke and Dr. Pepper
Good music to listen to
A friend to help you out

Step 2: Mounting the Gear Onto the Motor

Picture of Mounting the Gear Onto the Motor

OK, now you need to mount your gear onto the motor. Our axle was little too small to fit into the gear, so we wrapped it in some duct tape. We then used a copious amount of hot glue and some washers to hold it in place.

Step 3: Mounting the Gear and Motor Onto the Bike

Picture of Mounting the Gear and Motor Onto the Bike

Gee, we sure are doing a lot of mounting today! OK, this part is easy, you just need to put the motor setup on the bike in a way that the chain will catch on the gear and spin the motor. Its easy to do this with some hot glue, zip ties, and duct tape.

Step 4: The Wires!

Picture of The Wires!

OK, now for the electronics, just cut the head off of your charger and strip the wires off of it, and then solder them to the motor. You may have to use some resistors depending on the voltage that your cell phone takes. You can also wrap the finished product in some colored tape to match the bike like we did!

Step 5: Connect the Cell Phone and Ride Off Into the Sunset!

Picture of Connect the Cell Phone and Ride Off Into the Sunset!
OK! You are done! Just put your chain on the gear and ride off into the sunset! Thanks for reading!


stuffdone (author)2015-08-04

You can just get a $15 bike generator complete with head and tail lights. Simple voltage regulator if you like.

ukeboyska (author)2015-07-21

Alternatively, a decent, cheap product that does this (and way more) is finally on the market:

SkyKing101010 (author)2015-05-05

This is a great idea. If I could still ride a bike I'd be thinking about a way to modify it to charge a 12V motorcycle battery so I could run a CB radio or something from it.

The derailleur sprocket works beautifully. My main concern is the stability of mounting it using hot glue and duct tape. Wouldn't it eventually jiggle out of position because of bumps and changing gears and so on?

Also, the dynamo is a great idea (we used them for bicycle lights when we were kids), and it gives enough voltage to charge a phone no problem, but I'd use a bridgerectifier to change it to pulsating DC, and a proper capacitor filter it out to smooth DC. I'm pretty sure you wouldn't need to regulate the voltage, but I don't know what to do with the extra amperage so charger doesn't burn out the battery. Hmmmmm

CanadianGamers (author)2014-05-12

How many volts does it have to be 12?

azhar12 (author)2013-12-17

how much current it can produced

Nharzhool (author)2013-09-26

Has anybody thought of putting the motor on a short portion of slider (like from a drawer) so that it can move laterally when changing gears?

When I get myself a bicycle, will go through all of this.

Also thinking of slapping the rectifier in there with a regulator and rechargeable batteries. Thanks TheWelfareWarrior and flaresam for all of this.

tmoupo (author)2012-11-24

nice one dudes,now this is exactly what DIY is all about

imakethings (author)2009-04-25

Not a good idea as the motor will spin only when the rider must attach the motor directly with the wheel so that it generates voltages constantly

alexsolex (author)imakethings2009-04-26

maybe it is not a big problem, I don't know exactly if there's a matter with charging/not charging/charging/not charging.. for the phone. One biggest problem may be to regulate the current as it will only depend on how fast you peddle... the author (sorry, i can't find he's name on the instructable ??...) may need to test it a whole ride, wit a multimeter attached to it to know how much max/min voltage/current it can deliver anyway, i'm pretty surprised how the idea is so simple... in the past we used to have a "dynamo" (it may not be the correct English name) to light the bike. It was a kind of motor pushing pretty hard on the pneumatic, and making harder to peddle. This solution, using the chain, may be lower constraint.

flaresam (author)alexsolex2009-04-26

It is interesting, when we started, the battery was out of power, and when we biked the phone did not say it was charging. But afterwards, we checked the battery with a multimeter, and it was fully charged.

Penru (author)flaresam2010-11-13

Great Idea!!! But I want your help to take it to the next level...

Here's what i have in mind, add a battery system (something like a Powerizer 12v 4200 mAh NiMH Battery for RC Car Boat should work and fit under seat). this battery would be used to run headlights, tail lights/turn signals and also power my droid phone (running a dash board app to give me speedometer, odometer, compass and gps. This would be accompanied by a 80cc slant head engine. Well that is my idea... Any help would be great!



rimar2000 (author)alexsolex2009-04-26

Today I use a cycle with a dynamo. It is very effective. I used a 4 NiMH pack of batteries, but the connectors I used were of such poor quality that I had to remove the batteries because they caused many problems.

Kiteman (author)alexsolex2009-04-26

The author is flaresam - it is to the right of the page, and was under the image that you clicked to get here.

flaresam (author)imakethings2009-04-26

We could not mount the setup directly on to the wheel. The wheel spins freely of the axle it is on, so we could not mount it onto the axle, we figured that the only way to get enough power out of it was to use the chain.

jesusfreek (author)flaresam2009-08-11

connect a small wheel to the motor and put the wheel rolling on the outside of the tire

hotrodbuild (author)imakethings2009-04-28

even if you could somehow do that, it would not generate electricity constantly due to stop lights. i like welfare warrior's idea. that way at stop lights you can continue your charging.

hotrodbuild (author)hotrodbuild2009-04-28

one more thing. like most serious riders, i peddle while going down hill, so the only time i would not be peddling would be at a stop light. for a lot of idiot bikers, however, stop signs aren't even a problem because they don't pay attention to them, which annoys the crap out of me.

Wasagi (author)2010-06-07

Excellent! Just to clarify, any old DC motor would work, right?

imakethings (author)2009-04-29

no you cannot charge that way as it will reverse the polarity

Agroking (author)imakethings2010-01-18

 He uses a diode to change from alternating to direct.

Glockenator (author)2009-12-14

can you change the gears while charging the phone?

sharlston (author)2009-10-28

the little gear is from a derailer

try putting some lube on the chain

jjbalogh (author)2009-05-08

How do you change gears??

jesusfreek (author)jjbalogh2009-08-11

put it on a cruiser, no gears

flaresam (author)jesusfreek2009-10-02

This would also work quite well. Changing gears has become a bit of an issue.

flaresam (author)jjbalogh2009-05-08

Its far enough up so that you can change gears without a problem.

BigMac96 (author)2009-07-14

Could this work on an exercise bike?

omnibot (author)BigMac962009-08-28

If it doesn't have a chain a rubber roller against the flywheel should do.

bombmaker2 (author)BigMac962009-07-30

if it has a chain

and-reas (author)2009-08-23

That's a great way to charge! Here in Holland we have dynamo's on our bikes (little generators actually), with a cap on the axe (you know, that round thing in a geerator) that's pressed to the side of the front wheel with a sort of spring. It gives a 6v ac current from about a half amp. Straighting it out with some diodes and a capacitor should also charge up a phone i think. Why I'm saying this? Less risk of your chain breaking off because of the extra strain put on it. Not that your solution is bad, not at all, it's even less friction then my idea, but this is also an idea I just came up with ;)

RaWTHentic10 (author)2009-08-10

just wondering does it matter want kind of engine u use and if so whered you get yours from

fyrefox (author)2009-06-27

so when you change the gears it really doesnt mess with it.. cuz it seems like if you shifted to the smallest chainring in the back it would not be in line with your little wheel. did you get a chance to do anymore testing after the component conflict seen on your video?

dfedde (author)2009-06-09

if were to build this i wold add a power supply and a small capacitor bank so you can keep a constant charge even when your not moving for a short time i.e a stoplight.

zplatt (author)2009-05-12

Where did you get your DC motor? did you scavenge it off of something? How do you know if it's the right one and prevent frying your cell phone's battery?

bassmasta1010 (author)zplatt2009-06-03

you can find the exact same motor in a cd player, and those mini handheld fans

flaresam (author)zplatt2009-05-12

I just had it in my junk box =3
Test it with a multi meter and if you want, use a voltage regulator like aandre said. Oh, and use a powerful enough diode to change the current from ac to dc.

natelawrence (author)2009-05-27

Great Idea

TheFoerignMan (author)2009-05-23

great idea! would try it if it wasnt for one problem (unless you've explained it and i missed it)... what happens when you change gear? the chain will move and change position so you will have to change the generator's gear so that it matches the new position of the chain...

is this directed solely to those who dont change gears at all? cos thats what i do but i'll be getting a new bike, and i'll be using the gears a lot

but great idea!! =D

vince086 (author)2009-05-11

This is actualy a realy good idea, needs a bit more work but the idea is good. I was planing on making one of these but that used the weel, only problem was that with a dual suspention bike there is no space! So for that type of bike your idea is way more practical!

aandre (author)2009-04-28

This is an amazing concept and the only thing i would change would be to add a voltage regulator. When you ride a bike, you change speeds, even if it is unnoticeable. You have the potential to break your phone without a voltage regulator and I am surprised you didn't do so already.

flaresam (author)aandre2009-04-29

Thanks! We used a diode (AC to DC current), and the motor did not put out a high enough voltage to brake the phone. Again, if hotrodbuild (Jack) ever wants to update his bike charger, then thats what we will do.

imakethings (author)2009-04-26

IF the generator is attached to the wheel it will generate more power without much effort - i guess

imakethings (author)2009-04-26

To charge your mobile you will have to peddle continuously which is not possible!

rimar2000 (author)imakethings2009-04-26

It is not possible? That depends where you live and who are you!

rimar2000 (author)2009-04-26

Good idea, good instructable. I think you should place the charger in the bottom segment of the chain, to avoid overloading the shaft of the generator. Where you've located it, this receives part of the force applied on the pedals, when you use a front or rear gear littler that you used when aligned. Pardon if you don't understand my idea, I speak Spanish.

lemonie (author)2009-04-26

Put some chain-lube on your bike! (Good build) L

flaresam (author)lemonie2009-04-26

Thanks! Trust me, there was plenty of chain-lube on the bike, it was all over my hands afterwards!

lemonie (author)flaresam2009-04-26

Is that the stuff that's like glue, or is it only motorbike chain-lube that's that sticky..? L

flaresam (author)lemonie2009-04-26

Sticky, really sticky...

lemonie (author)flaresam2009-04-26

I friend of mine sprayed a bicycle-seat with chain-lube for a joke, didn't come off... L

About This Instructable




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