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

Step 2: Making Some Holes

Use a drill or a pointy object to make some holes located on the bottom and lower side.

Step 3: Adding the Carbon Rod (Positive)

Glue the carbon rod in place as the positive rod. The carbon rod is from a used AA battery.
Warning: Never open alkaline "it is messy".

Step 4: Adding the Foil (Negative)

Glue the foil in place as the negative plate.

Step 5: Connect the Water 's Wires

Connect the wire of the water battery, and glue it so it won't leak. Positive wire connected to carbon rod while negative is connected to the foil / zinc.

Step 6: Disassembling the Calculator

Disassemble the calculator with a screwdriver.

Step 7: Connect the Water Battery to the Calculator

Connect the water battery to the calculator. The carbon rod is positive while the aluminum is negative. Be sure to disconnect the solar panel.

Step 8: Assemble It Again

Put it back together again.

Step 9: Fill the Water Battery

Liquid Rating:
Water - Good
Water With Salt - Better
Vinegar - Best

Step 10: You Are Done

You are done. You just need to refill it a again after it run-out of power. Adding more water batteries would be better.

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167 Comments

thecrazymagnetman

10 years ago on Introduction

Amazing!

shalo

11 years ago on Step 3

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:)

austinbro217

11 years ago on Step 9

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!

dagob

11 years ago on Introduction

What an interesting instructable! Thanks for sharing!
I think you should explaing why it works (scientifically)

Pranjal Joshi

11 years ago on Introduction

this is marvelous project...!!
bt u cn do better with carbon n zinc rod using general acids.. :) wel done

aschmois

11 years ago on Introduction

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.