HOW TO – Homemade gravity-cell batteries powers a string of LEDs

Popular Science’s Theodore Gray show you how to power a string of LEDs using a chain of five homemade gravity-cell batteries – Link.

Related:

• Tomato soup battery and more – art by Ben Woodeson – Link.
• Penny-Powered LED – Link.
• Powering LEDs costs mere pennies – Link.

From the pages of MAKE:

• Penny-Powered LED. Power an LED with some salty water and $1.21. Subscribers–read this article now in your digital edition or pick up MAKE 07 in the Maker store.