NOVELTY - A battery pack is manufactured by accommodating a core pack containing a unit cell in an exterior case having flat square shape and two opposing surface parts; and potting by hardening a resin composition filled in the exterior case and by making a gap between the exterior case and the core pack into a flow path. The first surface part of the exterior case serves as a ceiling part. The ceiling part is provided with a filling port (20b) that is filled with the resin composition and a gas exhaust port.    USE - Method for manufacture of a battery pack.    ADVANTAGE - The method allows a potting process without restrictions on dimensions and layouts.    DETAILED DESCRIPTION - Manufacture of a battery pack comprises accommodating a core pack containing a unit cell in an exterior case having flat square shape and two opposing surface parts; and potting by hardening a resin composition filled in the exterior case and by making a gap between the exterior case and the core pack into a flow path. The first surface part of the exterior case serves as a ceiling part. The ceiling part is provided with a filling port (20b) that is filled with the resin composition and a gas exhaust port. The gap is divided into first filling space (S1) and second filling space (S2). The resin composition is filled into a part of the first filling space in a state which inclines the bottom face part (21) of the exterior case with respect to a horizontal surface (Ph) so that the second filling space is higher with respect to the first filling space. The resin composition is further filled in the gap in a state such that the bottom face part of the exterior case is in a horizontal state before the liquid level of the resin composition reaches the exhaust port.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram illustrating a potting process. Drawing includes non-English language text.    Front case (20)    Filling port (20b)    Bottom face part (21)    Funnel (50)    Horizontal surface (Ph)    First filling space (S1)    Second filling space (S2)