Abstract: According to the present invention an improved insulator cup, or case liner, enhances electrode coil insertion by reducing the possibility of damage to the coil during insertion, protects electrode and separator from laser radiation during welding, and eases manual inspection of partially assembled components, among other advantages. The improved insulator cup includes a mechanical joint, or hinge-like feature, which pivotably couples opposing parts of the cup and greatly enhances coiled electrode insertion and subsequent component inspection prior to sealing a cover member over an electrode assembly disposed within a housing. The mechanical joint can comprise additional parts that adhere to a divided insulator cup or can be formed as an integral part of an insulator cup (e.g., a linear area of reduced thickness, of apertures, and/or perforations, etc.).