Battery pack for electric vehicle

To provide a battery pack for an electric vehicle capable of enhancing the strength of the entire side wall of a tray, a battery pack for an electric vehicle includes: a tray 3; and at least one outer frame 6 disposed on an outer side of a side wall surface of the tray 3, the outer frame 6 extending along the side wall surface and being welded thereto so as to cover the side wall surface. The at least one outer frame 6 includes: a first protruding section 61 welded to an outer bottom surface of the tray 3; a second protruding section 62 positioned above the first protruding section 61 and formed to protrude outwardly from the tray 3; an outer section 64 connecting the first protruding section 61 and the second protruding section 62 at a position outwardly spaced from the side wall surface of the tray 3; and an inner section 63 extending from the second protruding section 62 toward the first protruding section 61 and being welded to the outer surface of the tray 3. The first protruding section 61, the second protruding section 62 and the inner section 63 form a part of a closed cross section, and the outer section 64 includes an aperture 6421 through which a welding gun G for welding the side wall surface of the tray and the inner section 63 is insertable.