Instructables user The King of Random gave us permission to share his cool project that teaches you how to build a battery with the spare change in your pocket. In just a few steps, a handful of pennies can power a small calculator or an LED bulb.
To complete both the calculator and LED project you'll need:
13 pennies, dated 1982 or later
an electrolyte such as vinegar, lemon juice or salt water
a small, cheap calculator
one or two LED bulbs