What is the procedure of a lemon battery experiment?

electrical current is the flow of electrons (movement) of an electrical charge and is measured using an ammeter. Solid conductive metals contain large population of free electrons, which are bound to the metal lattice and move around randomly due to thermal energy. When two terminals of a voltage source (battery) are connected via a metal wire, the free electrons of the conductor drift toward the positive terminal, making them the electrical current carrier within the conductor.