A
primary cell is a
battery that is designed to be used once and discarded, and not recharged with electricity and reused like a
secondary cell (rechargeable battery). In general, the
electrochemical reaction occurring in the cell is not reversible, rendering the cell unrechargeable. As a primary cell is used,
chemical reactions in the battery use up the chemicals that generate the power; when they are gone, the battery stops producing electricity and is useless. In contrast, in a
secondary cell, the reaction can be reversed by running a current into the cell with a
battery charger to recharge it, regenerating the chemical reactants. Primary cells are made in a range of standard sizes to power small household appliances.