Module vs. Pack: The Engineering Differences in EV Architecture (2026 Guide)
Release time:
2025-12-01
Battery Modules are intermediate assemblies consisting of multiple cells connected in series/parallel, providing structural protection and thermal management. A Battery Pack, on the other hand, refers to an assembly with multiple modules or cells in CTP connected in series/parallel with BMS (Battery Management System), cooling system and high voltage connectors ready for vehicle integration.
Battery Modules are intermediate assemblies consisting of multiple cells connected in series/parallel, providing structural protection and thermal management. A Battery Pack, on the other hand, refers to an assembly with multiple modules or cells in CTP connected in series/parallel with BMS (Battery Management System), cooling system and high voltage connectors ready for vehicle integration.
Newcomers to EV manufacturing may find the terminology difficult. Is a "Pack" just an over-sized "Module"? Not quite.
Understanding the hierarchy between Cell, Module and Pack stages is vital in designing your production line as each stage requires different automation equipment and testing standards.
1. The Battery Module: The "Building Block"
This module bridges chemistry and mechanics, performing tasks of compression and insulation.
Process Focus: CELL STACKING: Applying precise pressure to compress foam pads.
Busbar Welding provides laser welding cells in series/parallel configuration.
Insulation: Blue film wrapping or UV coating for insulation purposes.
Key Metrics: Energy Density (Wh/kg) and Electrical Isolation (5kV Hipot).
2. The Battery Pack: The "System"
The pack is where the battery becomes an integral component of a vehicle and its primary goal should be Management and Safety.
Process Focus: Module Integration: Joining or fastening modules onto the tray.
Thermal Management: Integrating liquid cooling plates and hoses.
Installing the BMS: Connecting its "Brain".
Key Metrics: System Voltage (400V/800V) and Crash Safety.
3. The CTP Revolution: Skipping the Module?
Cell-to-Pack (CTP) technology such as that used by BYD Blade completely removes modules.
Advantages: Increased cell count per space available (meaning more cells occupying same amount).
Manufacturing Change: For structural beams, manufacturing change requires longer laser welds with higher precision to secure them firmly to their bases, and no alternative modules to swap out should one become defective.
Huiyao's Role: Our welding lines are CTP-compliant, capable of deep penetration welding for chassis integration.
Which Line Do You Need?
No matter the scale or scope of your automation needs - Module Line, Pack Line or CTP Line - our engineers design automation to fit into the architecture of each facility.
Explore Our Solutions: Battery Production Lines.
AUTHOR: The Huiyao Laser Engineering Team
A collective of solution architects and process engineers at Huiyao Laser, 100% dedicated to solving the core bottlenecks in EV and ESS battery manufacturing.
© 2025 Huiyao Laser Technology Co., Ltd. All Rights Reserved.
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