Primary Cell Batteries

Combinations of certain metals (i.e. Copper and Zinc) will produce electrical activity when placed in special solutions called "electrolytes." The two metals form the "electrodes." The electrolyte creates a chemical action that causes the Zinc to form positive "ions" and the Copper to form negative "ions." These ions are freely flowing in the electrolyte. No current flow can occur until the "Electrode Terminals" are connected to a Circuit (i.e. a Light Bulb). The Electrons then flow from the Zinc Electrode through the external Circuit to the Copper Electrode. The chemical reaction between the Zinc and the electrolyte continues, and the Zinc is eventually used up in the process.

Common Dry Cell Batteries work on a similar principle with a "paste-like" electrolyte and a Carbon Electrode rather than Copper.