Batteries and accumulators belong to devices in which the chemical energy of active substances contained in them is converted into electrical energy as a result of chemical reactions taking place and are defined as chemically current sources.
The basis of the chemical power source is a set of active substances and electrolyte. In batteries and accumulators, this set operates in the form of a cell containing positive and negative electrodes and electrolyte in an individual enclosed housing. The cells function as direct current sources and, depending on the type of chemical reaction, are divided into:
primary cells in which the production of electricity takes place as a result of an irreversible chemical reaction and are not intended to be charged by other sources of electricity.
secondary cells in which the production of electricity takes place as a result of a reversible chemical reaction and are intended to be charged by other sources of electricity.
The (primary) battery is defined as one or more primary cells, including the housing, terminals and labeling.The accumulator (electric) is a chemical source of electricity that enables multiple storage and electric energy transfer as a result of reversible energy transformations.Each electrochemical system used in the cell is characterized by voltage. Appropriately, the approximate voltage value determined as the nominal voltage is used to identify batteries and accumulators. For practical reasons, cell assemblies connected in series to obtain the required voltage values are used.