Battery Module
A battery module is an interconnected and protected group of battery cells designed for use alone or with other modules. In many EV batteries it forms an intermediate level between cells and the complete pack, but that level is optional: cell-to-pack architectures reduce or omit conventional module housings. EUR-Lex: Regulation (EU) 2023/1542 on batteries and waste batteries
What a module does
A module can organize cell interconnections, compression or support, thermal interfaces, voltage and temperature sensing, terminals, and local protection. These are common design functions, not a mandatory checklist for every module. The grouping creates a manageable electrical and mechanical unit for pack assembly and testing. Argonne National Laboratory: A Manual for BatPaC v5.0
A module is not the vehicle's complete traction battery. Its cell count does not by itself reveal pack energy, voltage, safety, or serviceability. A pack that contains modules is not automatically repairable, while a module-free design still needs cell support, electrical connections, monitoring, cooling, and protection elsewhere.
For the deeper architecture and configuration explanation, see Battery Pack & Configuration.