Diybattery 485
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.

Img M590
From the pages of MAKE: