An intermediate battery assembly made from cells and designed to sit inside a larger pack or battery system.
Battery module is a granularity bridge between cell evidence and pack-level operation. It matters for traceability because faults, replacements, chemistry groups, and test results may be isolated to one module rather than the entire pack. The source boundary should keep cell, module, and pack distinct, including the U.S. 45X context where module language serves a manufacturing-credit function.
Module language should remain separate from cell and pack language even when a source definition lists cells, modules, and packs together. The module is a parent-child assembly layer, not a generic synonym for battery component.
Regulation (EU) 2023/1542 concerning batteries and waste batteries
any set of battery cells that are connected together or encapsulated within an outer casing to protect the cells against external impact, and which is meant to be used either alone or in combination with other modules;
Reference: Article 3, point 3
26 U.S.C. § 45X - Advanced manufacturing production credit
a module— (I) (aa) in the case of a module using battery cells, with 2 or more battery cells which are configured electrically, in series or parallel, to create voltage or current, as appropriate, to a specified end use, or (bb) with no battery cells, and (II) with an aggregate capacity of not less than 7 kilowatt-hours (or, in the case of a module for a hydrogen fuel cell vehicle, not less than 1 kilowatt-hour).
45X uses a manufacturing-credit-focused definition with explicit module structure and aggregate-capacity thresholds.
Reference: 26 U.S.C. § 45X(c)(5)(B)(iii)
Reviewed public draft page. Aligns with high-priority battery section-role policy: plain working definition, concise source boundary, concrete implementation objects, and evidence-focused commentary.
Battery module is an intermediate assembly of cells that is not usually the final battery product on its own. It provides a structure for grouping cells before they become part of a pack or larger battery system.
This term is defined in U.S. law (26 U.S.C. § 30D or § 45X) and is not part of EU regulatory vocabulary. It is included in this glossary because battery manufacturers and EV producers operating in both the EU and US markets need to navigate both legal frameworks simultaneously. Definitions in US and EU law for similar concepts (e.g. battery cell, battery module) are not identical and should not be treated as interchangeable.
Implementation records should capture module identifier, cell set, chemistry grouping, manufacturer or assembler, pack assembly link, test evidence, repair or replacement event, and any serial/batch relationship needed to trace the module through service or second-life workflows.
Battery module records keep cell-level evidence usable at pack scale. Structured module links make it possible to trace faults, replacements, and second-life decisions without over-claiming that the entire pack shares the same condition or history.