To create a battery at home all you need is some copper wire, zinc coated screws (or nails), plastic ice cube tray, and some salt water (you want it non-drinkable, or extremely salty). There are quite a few ways to make batteries at home with minimal trips to the store for materials. The piece of wire on the bottom left side of the tray is the anode or the positive side of the battery. The liquid in the tray is the electrolyte that allows the electrons to travel from the screw down the wire and to the other screws. This process continues until the electrons meet the end of the route. On the right side is an extra screw with a piece of wire hanging out of the tray, that is the cathode or the negative side.