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Penny Battery

1 article
5 videos
Can you light up a room with just five cents? A battery is a device that converts chemical energy into electrical energy. This activity, developed and demonstrated by Julie Yu, director of the Exploratorium Teacher Institute, shows you how to build a battery strong enough to power an LED for a whole day—using nothing more than a few pennies and a salty solution. Watch the videos to learn how to build a battery of your very own, and light the way for other chemistry lovers.

Penny battery introduction

VIDEO 0:19 minutes
You can make a simple battery, powerful enough to light an LED, with the change in your pockets!

Build your own penny battery: Materials & steps

VIDEO 5:51 minutes
In this video, you'll find the materials and tools you'll need to build your own penny battery, as well as all the necessary steps. 

What's going on: Chemical energy into electrical energy

VIDEO 1:11 minutes
What's the science behind this activity? A battery is chemical energy converted into electrical energy.

Challenge: Design a more powerful battery

VIDEO 0:31 minutes
So now you know how to light a red LED. What about a blue one? Hint: a blue LED requires more power.

Challenge solution

VIDEO 0:36 minutes
A four-cell battery generates 2 volts, but we need to generate 3 volts to light the blue LED.