Picture of Water Powered Calculator (Original)
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

Picture of 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

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shalo3 years ago
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:)
ASCAS (author)  shalo3 years ago
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!
ASCAS (author)  austinbro2173 years ago
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.
dagob3 years ago
What an interesting instructable! Thanks for sharing!
I think you should explaing why it works (scientifically)
this is marvelous project...!!
bt u cn do better with carbon n zinc rod using general acids.. :) wel done
aschmois4 years ago
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.
ASCAS (author)  aschmois4 years ago
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
ASCAS (author)  aschmois4 years ago
Yeah (:D) try adding a joule thief powering a LED bulb. It should work.
jmcdermott4 years ago
silly matrix, inside duh
chaitanyak5 years ago
most innovative - yet simple thing i found today! Good job!
Dipankar5 years ago
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.
artworker5 years ago
Innovative. Nicely done! It's sad that teachers don't encourage these projects in school! Every student should know these tricks. 5*
ista rita11 months ago

Its amazing!
anyway, can I use copper nail instead of copper rod?

Yeah. It's copper anyway.
mohd hashir2 months ago
SanjayK11 year ago

can you say where did you get the carbon rod? I made it with a graphite(pencil lead)but it doesn't work

I think you can get some out of c or d cell batteries.
ista rita11 months ago

Its amazing!
anyway, can I use copper nail instead of copper rod?

I luv it!

You gave me an excellent idea to be used at the science fair project.

But will you allow me to use it?

mlee wei1 year ago

wow lol so nice but how many volts is dat

Himers1 year ago

How long does the battery last and how many volts does it generate?

ASCAS (author)  Himers1 year ago

2 weeks, as long as you keep it wet.

Can i use insulated copper wire instead of bare copper wire?
Can i use battery calculator instead of solar powered?
ASCAS (author)  franceserikey1 year ago

Yup! there's no difference I suppose.

Can you pls send me a video on how to do the water powered calculator
ASCAS (author)  franceserikey1 year ago

Just replace the LEDs with a calculator :)

lteodoro1 year ago

What kind of wire is used for the Water Powered Calculator?

ASCAS (author)  lteodoro1 year ago

Bare Copper Wire :)

ABC2XYZ1 year ago
How many volts does it produces?Is it enough to light up LED.
ASCAS (author)  ABC2XYZ1 year ago

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.

Click Me: Water Powered Flashlight

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

ASCAS (author)  xMontyPythonx1 year ago

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.

i did not use cotton do i need to?

ASCAS (author)  xMontyPythonx1 year ago

No, I used tissue paper but you can use any type of porous material.

Why don't you answer my q's
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