Battery Cell
A battery cell is the functional electrochemical unit that converts stored chemical energy into electrical energy and can be recharged when its reactions are reversible. It contains positive and negative electrodes, an electrolyte, terminals, an enclosure and, where the design requires it, a separator.
Cell, module and pack
A cell is not the complete EV battery. Many cells are electrically connected and mechanically supported to create the voltage, energy and power required by the vehicle. A module may provide an intermediate assembly, while the battery pack forms the complete unit installed in the EV.
Cells can use different chemistries and physical formats. These choices affect packaging, cooling, structural support and manufacturing, but a cell label alone does not determine the performance of the finished vehicle battery.
For cylindrical, prismatic and pouch constructions, see Cell Formats.
Why it matters
Cell voltage, capacity, internal resistance, temperature and consistency all influence the pack. Pack-level voltage and energy also depend on how many cells are connected in series and parallel, while usable energy is further shaped by operating limits and battery management.