NOVELTY - The battery pack comprises a battery including a battery element (10) covered with a packaging member, a protection circuit board (32) for the battery, and a covering material (18) collectively covering the battery and the protection circuit board. The battery element includes positive and negative electrodes, which are spirally wound together or stacked on one another through a separator. The covering material includes a shape-retaining polymer, and is a composite material including the shape-retaining polymer and a filler material. The covering material has a glass transition temperature.    USE - The battery pack is useful as a portable power source for the electronic devices such as camera-integrated video tape recorders, cellular phones and laptop computers, as a secondary battery for high power applications such as an electric car and a hybrid car or as a battery for power tool.    ADVANTAGE - The battery pack can be easily manufactured with increased energy density, reduced size (thickness) and weight, high dimensional accuracy and impact resistance and improved mechanical strength, reliability and capacity.    DETAILED DESCRIPTION - The battery pack comprises a battery including a battery element (10) covered with a packaging member, a protection circuit board (32) for the battery, and a covering material (18) collectively covering the battery and the protection circuit board. The battery element includes positive and negative electrodes, which are spirally wound together or stacked on one another through a separator. The covering material includes a shape-retaining polymer, and is a composite material including the shape-retaining polymer and a filler material. The covering material has a glass transition temperature (Tg) of 45-130 degrees C as measured by differential scanning calorimetry (DSC). The packaging member for covering the battery element is an aluminum laminated film and a film composed of a single layer or layers, and includes a polyolefin film. An INDEPENDENT CLAIM is included for a method for producing a battery pack.    DESCRIPTION OF DRAWING(S) - The diagram shows cross-sectional views of a battery pack.    Battery element (10)    Covering material (18)    Protection circuit board (32)    Bottom-side cushioning material (33)    Top-side cushioning material. (34)