Things You'll Need
Instructions
Create a saturated solution of salt water by adding more salt than the water can dissolve. Pour the salt solution into another cup leaving the extra salt behind, this is the electrolyte used to create the battery.
Strip the outer plastic sheath from both the copper and zinc wires so six inches are left exposed. Coil both bare wire sections around the marker, these are the electrodes.
Tape the electrodes to either side of the cup containing the electrolyte; make sure the coils are completely immersed into the water. Connect a volt meter to the wires, there will be a potential different or voltage showing.