This Instructable will show you how to make a very simple water powered calculator.
I built this because there was a time that we forget to buy a supply of AAA, AA, C, D and LR44
battery so I built this. It solve my problems so it might do the same for you too. Check out for more projects by: angelo10.

This is the original version by: angelo10

Please give the credits to me not for your selves. I saw people getting my pictures and telling  others that they made it. Please don't get all the credits!

Proud to be Filipino (pinoy) like Manny Pacquiao.

Step 1: Meterials You Will Need

You will need:
- A Calculator
- Carbon Rod/ Copper Rod
- A 1x1 Inch Aluminum Foil
- A Small Cylindrical Container
- Two 3 Inch Wire
- Multi Purpose Pliers
- Glue Gun

aside from batteries where can you find those cooper rods? pls help im so desperate :( and im from the philippines as well so if you a pls tell me:)
It's hard to find one, probably in construction hardwares, they usually call it copper tubing. I made another design of the water battery by only using copper wire and nails. My new version is more efficient, more powerful and uses mor common materials.
Nice job man! I am just starting to explore electronics at 15 years old, and you are an inspiration for me to keep with it!
Thanks! But what ever you do, never give up, specially when you fail. Use your failures as your guide and try and try again, later on you will succeed.
What an interesting instructable! Thanks for sharing!<br>I think you should explaing why it works (scientifically)
this is marvelous project...!!<br>bt u cn do better with carbon n zinc rod using general acids.. :) wel done
Great tutorial, my first try I had water leaking from everywhere and only a mere .3-.5 volts. Vinegar is NOT the best solution. I have tried and what seems to work best is Lemon Juice and Salt. (water and salt is still better than vinegar). The picture has two batteries in series which add up to a good 1.5 volts. However, for some reason I cannot get a light to turn on. My guess is that voltage reading stabilizes with a circuit, but the bulb cannot stabilize. Might also be the amperage not being high enough.
Nice job. I recommend you to clean each carbon rod carefully, there's a lot of manganese sticked on it. Second both metals should not touch. Third if none of this work make 2 more of this in parallel
Yeah (:D) try adding a joule thief powering a LED bulb. It should work.
silly matrix, inside duh
most innovative - yet simple thing i found today! Good job!
How long does the battery work? Good Idea. Keep it up.
I think we have a good kid here. Now if he'll take after you.
Yeh! He's a bright kid. Hope he does well in life.
Innovative. Nicely done! It's sad that teachers don't encourage these projects in school! Every student should know these tricks. 5*
<p>Its amazing! <br>anyway, can I use copper nail instead of copper rod?</p>
Yeah. It's copper anyway.
<p>can you say where did you get the carbon rod? I made it with a graphite(pencil lead)but it doesn't work</p>
I think you can get some out of c or d cell batteries.
<p>Its amazing! <br>anyway, can I use copper nail instead of copper rod?</p>
<p>I luv it!</p><p>You gave me an excellent idea to be used at the science fair project.</p><p>But will you allow me to use it?</p>
<p>wow lol so nice but how many volts is dat</p>
<p>How long does the battery last and how many volts does it generate?</p>
<p>2 weeks, as long as you keep it wet. </p>
Can i use insulated copper wire instead of bare copper wire?
Can i use battery calculator instead of solar powered?
<p>Yup! there's no difference I suppose.</p>
Can you pls send me a video on how to do the water powered calculator
<p>Just replace the LEDs with a calculator :)</p><p><a rel="nofollow"><iframe allowfullscreen="" frameborder="0" height="315" src="//www.youtube.com/embed/un_uY3ffaMg" width="560"></iframe></a></p>
<p>What kind of wire is used for the Water Powered Calculator?</p>
<p>Bare Copper Wire :)</p>
How many volts does it produces?Is it enough to light up LED.
<p>My new version produces 0.6v - 0.9v and yeah it produces enough energy to power an LED, with the help of an inverter circuit of course (joule thief). In fact I was able to make a flashlight out of it.</p><p>Click Me: <a href="http://www.instructables.com/id/Water-Powered-Flashlight/" rel="nofollow">Water Powered Flashlight</a></p>
<p>Okay will someone please tell me why it looks like there is cotton in there, and tell me when i put it in there, since i believe there is some in there when do i put it in, and do i need to replace it every time i need to recharge it, because when i made mine i did not use cotton i only followed the instructions and it is not working for me. Neither the aluminium foil or the carbon rod are touching each other, the negative wire is touching the salt water. Will someone please tell me what i did wrong. Also i am going to be charging a home made capacitor, but ,beside the point, it is not having any output. Please help</p>
<p>The tissue paper became mushy because of its long exposure to water. A lot of people got this to work. Have you tried checking your battery's polarities? Try to connect a volt meter, check if the battery has an output.</p>
<p>i did not use cotton do i need to?</p>
<p>No, I used tissue paper but you can use any type of porous material. </p>
Why don't you answer my q's
<p>Sorry, it's exam week. I forgot to check my ible inbox for such a long time. After all, my studies are my priority :D</p>
Under what topic is this project related to? Thank you
Chemistry under Redox reaction :D
Thank you sir! Uhm Do you have any idea on how i can relate this project to the topic electricity in physics??
How much voltage and current do you get out of something like this?<br>And if you were to make it bigger or smaller, would that affect the voltage or current?
not the size but the surface area would make the difference
uy pilipino din ako <br>I was wondering if it would work when i fill it with urine i said that because i know that <br>urine has salt and water.
Probably, but that's grows and very unhygienic.
It is so easy opening SONY Alkaline batteries.

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