Introduction: Flashlight With No Batteries

Picture of Flashlight With No Batteries

This is a simple method to make a flashlight that will last forever.
It uses a small stepper motor to generate energy and many capacitors for keep it stored for several seconds.

Ps: I'm from Argentina so let me know any grammar mistake.

Step 1: Materials

Picture of Materials

Most materials are recycled from the trash.

You will need:
  • Two LEDs, with their silver led holdres.
  • An unipolar stepper motor with its reduction gear.
  • One or two broken PC motherboards, to remove the capacitors.
  • Two 220 ohm resistors.
  • A sheet of cardboard.
  • A small piece of plastic.
  • Plastic spacers.
  • Four rectifier diodes.
  • Spray paint.

Step 2: Prepare the Capacitors

Picture of Prepare the Capacitors

The key to the lantern is to put capacitors in parallel to be interpreted as one large-capacity capacitor.
I use 40 capacitors of 1000uf 10v.
If you use more capacitors the torch will stay lit longer.

Solder four rows of 10 capacitors each one.
Then solder the rows together.

Step 3: Make the Carboard Case

Picture of Make the Carboard Case

Draw the box on the cardboard.
Trim the excess parts and fold by the lines.
Paste a strengthening in the areas where the motor will be attached.
Use double-sided tape to close the box.
If your cardboardis very hard use scotch tape to keep it closed.

Use the pdf file attached as a guide.

Step 4: Paint the Cardboard

Picture of Paint the Cardboard

Paint the cardboard to make it look better and be more resistant to moisture.

Step 5: Prepare the Motor Connector

Picture of Prepare the Motor Connector

Solder the four diodes to the contacts of the individual coils of the motor in the male connector and a small piece of wire to pin cable which connects the common of the four coils.

Step 6: Finishing the Inside

Picture of Finishing the Inside

Solder the output of the four diodes to the positive of the capacitors and the wire to the negative.
Solder two pieces of wire on the opposite side of the capacitors.

Then insert it into the box.

Step 7: Leds

Picture of Leds

Cut the plastic about the size of the top.
Drill two holes for the led holders and paste.
Inset leds, solder two resistors in the positive terminals of the LEDs. Solder the negative together.
Then solder the wires coming out of the box and paste the plastic to the cardboard.

Step 8: Attach the Motor

Picture of Attach the Motor

Use a zip tie to attach the motor to the cardboard box, remember to connet it to the capacitors.

Step 9: The Handle

Picture of The Handle

Use a small piece of plastic and hte spacers to make a handle and paste it strongly to the motor gear.


ErnestoS (author)2016-10-24

Tenia pensado en hacer algo asi yo tmb. Nunca sabes cuando necesitas una para alumbrar a un demonio que es debil a la luz y que te ha destruido toda la iluminacion de la casa :P..

Creo que tengo un motor chiquito de continua(no paso a paso), capaz que pueda servir igual. Y concuerdo con que un envase de plastico ignifugo seria mas conveniente. Por lo demas, muy buen trabajo!.

TravisM18 (author)2016-01-22

Look up laser he had some joule looper circuit that relly conserve the power to run an led from a super capacitor.

n410gangwar (author)2010-11-15

can we use a charging circuit to charge some rechargable AAA batteries and use them in place of capacitors . They can turn the lights on for a long time.


joevyto (author)n410gangwar2016-01-16

The name of of the project is "Flashlight with no batteries" If you want a flashlight with batteries, there are millions out there in the store.

brooklynlord (author)n410gangwar2010-12-04

Rechargeable AAA batteries, depending on the type, will need a complex charger to prevent overcharging and it has to be at a certain voltage.

Those circuits are very complex, its not easy.

ChrisM257 (author)2015-12-28

what type of capacitors did you used

vero.escalona.94 (author)2015-03-18

Can I use a bipolar stepper motor instead?

michaelgc (author)2014-06-09

Great looking diy no battery light, I agree with crumpton that pvc or something would look better and be easier to carry.

macrumpton (author)2014-03-24

Great project, but for a project this nice I think you might do better to put the body in a plastic box like a tupperware, or maybe a piece of PVC pipe rather than cardboard.

PONG123 (author)2014-03-11

got all the parts but don't have time

Adambowker98 (author)2012-06-12

Could you just use several larger caps?

brunoip (author)Adambowker982012-06-12


Adambowker98 (author)brunoip2012-06-13

what size would you recommend if i just wanted to use about 3 caps?

chipper35 (author)2011-11-23

Maybe not the prettiest flashlight in the world.....but VERY cool!!

putty1cat (author)2011-11-05

Thank you, your 'ible and biotele's 'ible have inspired me. I am trying to make something similar using an old hand cranked torch. I used 4x 1500uf 6.3 volt. It seems very dim unless I crank it continually. biotele used a joule thief to brighten his but I was wondering does more voltage make it brighter? So you have used 10 volt capacitors if the capacitors were lower say 6.3 volt would the led be less bright. Or is your torch dim too?

putty1cat (author)2011-10-10

oh, this is a really good idea! Now to figure out, how would I do this with a battery pig of a camera.

zapper067 (author)2011-08-20

What can we do with the processors?

anuragmahajan152 (author)2011-08-06

Very nice instructable. Your idea is brilliant of using capacitors and stepper motor.Thanks.

sharktooth (author)2011-06-10

That's Excellent...

If you don't mind, I have some suggestions for you.....

You can add some more gears (you can find them in toy cars), so that,

when you complete a round of hand-crank, the motor will complete its 20 - 25 rounds...

arikyeo (author)2011-01-25

I think it would be more advisable to use just 2-3 supercaps in series... They can last for minutes. Just my 2 cents ;)

brunoip (author)arikyeo2011-01-26

that was my first idea, but they are harder to get than regular capacitors.

11rex11 (author)2010-10-18

i used some capacitors form a disposable camera the big one for the flash worked great

brunoip (author)11rex112010-10-20

Post a pic :)

11rex11 (author)brunoip2010-10-20

I made this several years ago But ill look for it i think i know where it is

johnbertquirabo (author)2010-10-02

does it necessary to use the same kind of stepper motor?

brunoip (author)johnbertquirabo2010-10-03

any unipolar stepper motor would be fine

zorba02008 (author)2010-08-26

can i use a stepper motor from dvd writer or hard drive ? but these motors i have has 12 pin output what can we do ?

awhh sorry the spaces didnt stay. You just have i diode leading into a pin and one leading outside.

where could i get the same kind of stepper motor used?

Well these types of motors are used in allot of things but probably the easiest would be a stepper motor inside a printer. You purchase larger motors but the printer stepper motors work very good.

the trick to find a good stepper motor is low rpm soo a hardrive would not work too well.... to get the most power from a stepper motor is to wire it up like this Stepper input o----||| |----o----||| |----o o----||| |----o----||| |----o o----||| |----o----||| |----o o----||| |----o----||| |----o Negative Positive this takes 2 diodes per pin, the pin is connected in the center and the diodes filter the power to give you a + and - output. The ||| represents the orientation of the diode.

brunoip (author)zorba020082010-08-27

Maybe it has two motors inside, try to get the datasheet.
Regards, Bruno

noeroldansiabox (author)2010-09-23

where can i get a recycled stepper motor?

noeroldansiabox (author)2010-09-23

does these capacitors cost much?

noeroldansiabox (author)2010-09-23

does it really last forever?

noeroldansiabox (author)2010-09-23

good day!!

how long will the light last if i will be using unrecycled capacitors?

brunoip (author)noeroldansiabox2010-09-23

the same ¬¬

noeroldansiabox (author)brunoip2010-09-23


noeroldansiabox (author)2010-09-23

good day!!

how long will thelight if i will going to use unrecycled capacitors?

matstermind (author)2010-09-05

what if you add a switch, them charge the caps for 10-30ish seconds. how long would the light last?

antling (author)2010-09-03

Nice and 2 thumbs up!

D5quar3 (author)2010-08-20

Just get like three super capacitors.

Just remember, they have to have low enough ESR.

Why do they need low ESR?

What I mean is that some of the super capacitors have very high ESR. The ESR just has to be like something less than 2 ohms.

Use some sort of joule thief like this one. It draws much less than 20ma, even with 2 LEDs on, and the LEDs are pretty bright too.

In this application a super cap is presented with DC mostly. While there would be a ripple current present, I'd think it would be low enough, that ESR wouldn't be a factor.

Supercaps with high ESR will not supply enough current to get full brightness from the LEDs.

xarlock667 (author)2010-08-29

Ummm.... I have an off topic question. Could this be used as a hand cranked stun gun? Seems to have enough capacitors wired correctly, just remove the lights and replace with two electrodes? Home made self defence tool for cheap?

magnamino (author)xarlock6672010-08-31

No.. it couldn't be used like a Standard stun gun. Stun guns have inductors as well as capacitors, which creates a sort of "tank circuit" when combined with the internal circuit and use two contacts to short it out across target.. However, removing the LEDs and placing two contacts out the front could be used to deliver a discharge of the caps. Don't know if you have ever picked up a charged cap before, but it hurts when it discharges across you. I will see what I can come up with for a Make-Your-Own stun gun.

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Bio: Robots and video games...
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