A lemon battery is a simple battery made for the purpose of education. Typically, a piece of zinc metal (such as a galvanized nail) and a piece of copper (such as a penny) are inserted into a lemon
Step 1: Potato Battery Homemade
Potato battery with zinc (left) and copper electrodes. The zinc electrode is a galvanized machine screw. The copper electrode is a wire. Note the labels − and + marked on the potato indicating that the copper electrode is the positive terminal of the battery. A short screw and nut connect the electrodes to the copper wires that have black and red insulating plastic coatings.
Step 2: Orange Battery DIY
Set the Orange on a table and gently roll it around to soften it up. You want the juice to be flowing inside the fruit without breaking its skin. Alternatively, you can squeeze the fruit with your hands.
Insert the zinc and copper nails into the fruit so that they are about 2" or 5 cm apart. You don't want them to be touching each other. Avoid puncturing through the end of the fruit.
Step 3: Salt Batteries Homemade
Molten salt batteries (also liquid metal batteries) are a class of battery that uses molten salts as an electrolyte and offers both a high energy density and a high power density