Lithium-ion is a collective term for many different chemistries and technologies. In general, most of the chemistries are based on creating energy through the movement of free ions between the anode and the cathode in a battery cell. A lithium-ion battery combines several of these cells to form a module. Depending on the size of the battery, several modules may be connected in series, forming a battery system. Each module has a battery management system (BMS), as does the entire battery system. The BMS monitors and controls factors such as battery charge and power consumption. The BMS works in cooperation with the truck. If any of the cells in the battery module are damaged or are in danger of overheating, the power supply is switched off and the truck indicates a fault code.