Batteries are too mainstream, let's make Water Powered ones! The DIY flashlight never runs out of batteries, water is all around us and will never run out. One of today's causes of pollution is the improper disposal of batteries containing heavy metals such as lead and mercury. The answer, using water as electrolyte!

Imagine, running wall clocks for 6-12 months with water, you'll never need to leave your house just to buy batteries and there's no need to recharge them. What could be more convenient than replenishing your batteries with tap water? :D

The flashlight runs 30mins continuously with tap water and 2 hours with saltwater. Not bad for a single celled prototype :D This thing also works well with calculators, clocks & radios Remember, adding a second cell triples the glow and lighting time! 

How Does It Work?
This is a type of battery called the "Galvanic Cell", having 2 different types of metals and is connected by a salt bridge. It works like your typical battery but uses water as its electrolyte. If you want to read more about how batteries work "click here" The output voltage is pretty faint and isn't enough to run a single LED. By the help our trusty "Joule Thief Circuit", the LEDs would glow even at low voltages.

Is It Really Powered By Water?
Well not really, the water serves as an electrolyte, a replacement for toxic chemicals used in regular batteries, which usually ends up in dumpsites. So why call it water powered? Of course no one would be interested in the title "Galvanic Flashlight" plus that's what easily pops up in people's minds. The Redox reaction takes place in this project.

Practical Uses:
1st.) If you got lost and stranded out in the woods, you can't rely on batteries, eventually they run out. A mini version would save stranded people in the woods. Just go to the nearest river and fill her up! Whala, you have light!
2nd.) School science experiment
3rd.) A fun and educational project for all ages!

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A Larger Scale Water Powered Project (a.k.a Galvanic Cell):

Step 1: Gathering Tools & Materials

Parts & Materials:   
- PVC Pipe 4" Long (3/4"‎Ø)  [Local Hardware]
- PVC Coupling 3/4" to 1" [Local Hardware]
- Recycled 3xLED Torch  [Inventory = Free]
- Toroidal Core/ Bead  [Recycled From CFL Bulb]
- 2N3904 Gen. Purpose NPN Transistor [Radioshack] 
- 1K Ohm Resistor (1/4w) [Radioshack]
- Cooper & Zinc Strip  [Local Hobby Shop]
- Magnet Wire/ Copper Wire [Inventory/ Local Hardware]
- 4 Sheets Of Tissue Paper [Toilet/ Bathroom]
- 2x2" Sheet of Acetate [Bookstore/ Office Supplies]

Tools & Equipment:
- Leatherman MultiTool
- Soldering Iron
- Hot GlueGun
- Teflon Tape
- Super Glue

About This Instructable


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Bio: Join me as I build fun and random weekend projects!
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