The Backbone of EV Power: Cells, Modules, and Battery Packs

In the power system of new energy electric vehicles, the battery system follows a strict hierarchical structure comprising cells, modules, and battery packs. Together, they form the core energy source for EVs:

Cell

Cells are the basic energy storage units, determining critical performance factors such as energy density, charge/discharge performance, and lifespan.

• Function: Provides foundational energy for battery modules.

• Busbar Type: Battery tabs or copper foil flexible connectors are recommended for their excellent conductivity and flexibility, reducing resistance and heat loss in current transfer.

Module

Battery modules are intermediate assemblies, combining multiple cells in series and parallel. They are integrated using mechanical structures and busbars.

• Function: Consolidates voltage and capacity while improving safety and reliability through electrical protection.

• Busbar Type: Flexible copper or aluminum busbars are ideal for their flexibility and vibration resistance, enabling compact layouts and simplifying internal connections.

Battery Pack

Battery packs comprise multiple modules and integrate components such as the battery management system (BMS), thermal management, and structural enclosures.

• Function: Delivers stable, efficient power output to the vehicle while ensuring thermal management and system safety.

• Busbar Type: Extruded copper or aluminum busbars are suitable for high current applications, offering superior insulation. PVC-coated rigid busbars are recommended for high-voltage environments, providing enhanced safety and durability.

Battery Busbar Types and Their Advantages

• Thin Copper Connector: Designed for internal micro-connections between cells, offering excellent high-frequency charge/discharge performance for efficient energy transfer.

• Copper Foil Flexible Connectors: Provide outstanding flexibility and shock absorption, making them ideal for connections between cells and modules, accommodating slight movements while ensuring stable conductivity.

• Flexible Copper/Aluminum Busbars: Used for module internal or inter-module connections. These battery busbars offer strong flexibility and vibration resistance, with aluminum busbars providing the added benefit of weight reduction for optimized module design.

• Extruded and PVC-Coated Rigid Busbars: At the battery pack level, insulation and safety become critical. Extruded rigid busbars and PVC-coated rigid busbars combine excellent insulation properties, high mechanical strength, and superior conductivity. They are well-suited for high-voltage main bus connections, power output terminals, and charging interfaces, delivering reliable performance in demanding environments.