The process begins with cylindrical logs of a specific aluminum alloy (commonly from the 6000 series, like 6061 or 6063, for their good strength and extrudability). These billets are pre-heated in a furnace to a precise temperature (typically between 400 - 500°C). This thermal treatment softens the metal, making it pliable enough for extrusion without melting it.

The heated billet is loaded into the extrusion press. A hydraulic ram applies immense pressure, forcing the softened aluminum through a precision-engineered steel die. The die's opening defines the housing's final cross-sectional profile, including its external walls, internal ribs for structural support, and channels for thermal management or cable routing. The emerging profile is a continuous length of the shaped aluminum.

As the profile exits the die, it is rapidly cooled using air or water quenching. This "freezes" the profile's shape and initiates the strengthening process. The long, straight profile is then mechanically stretched. This critical step corrects any twisting or dimensional irregularities and aligns the metal's grain structure.

The profiles undergo artificial aging (precipitation hardening) in an oven. This heat treatment allows the alloy's microstructure to fully develop, bringing the aluminum to its specified temper (e.g., T5 or T6) and achieving its final mechanical strength and hardness. The hardened profiles are then cut to the precise required lengths for individual battery housings.