The lithium-ion battery is composed of elementary units, called modules, stacked (number and layout) according to capacity needs and architecture constraints.

Each module contains 4 battery cells, in which take place reversible electrochemical reactions, allowing to produce electrical current (battery in discharge) or to store energy (battery in charge).

During the battery is in discharge, the lithium ions move from the anode to the cathode. This reaction causes a flow of electrons (electrical current) in the supply circuit. When the battery is in charge, the opposite reaction happens.