Kid Maker How-To: Make a Salt Water Battery

Is your child looking for a science project? Try this idea for a DIY battery.
By Kevin Goodwin

Ages

9-13


A battery works when electricity is produced by something called an oxidation/reduction (redox) reaction.  

In this project, you and your child (adult supervision is required) use two different metals and some salty liquid to create a redox reaction.  One metal will oxidize and lose electrons.  The other will reduce and gain electrons in the process. These reactions can result produce toxic chemicals, so use these precautions:

  • Wash hands before and after experimenting with batteries and electrolytic cells.
  • Experiment only in a well-ventilated space.
  • Wear latex or nitrile gloves.
  • Do not reuse containers you use in this project for food or other non-science purposes.

What Does That Mean?
A redox reaction is a chemical reaction involving the transfer of electrons.  It's what's happening when metal rusts, fires start, photosynthesis happens in plants, and we breathe by inhaling oxygen and exhaling carbon dioxide.

Materials & Tools
Water
Salt
Nonmetallic jar or bowl  (glass or plastic)
Different types of metal objects: paper clips, coins, nails and screws, etc.

Alligator Clips
Voltmeter

Directions
Step 1:  Make Salt Water
Pour 2 cups of water into your jar or bowl.  Pour 1 tbsp. of salt into the water and mix until dissolved.

Step 2:  Set Up Your Leads
Connect one alligator clip to one metal object and connect a second clip to a second metal object.

Dip the objects into the salt water.  Don't let the alligator clips touch the salt water.  

Step 3:  Testing
Attach the clips to your volt meter and see how much voltage the battery is producing.

Step 3:  Iteration
Try different combinations of metals and liquids to see what results you get.

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