A vehicle power source arrangement comprising: - a vehicle power source, and - at least one reinforcement structure (13a, 13b, 13c, 13d, 13e, 13f) said reinforcement structure (13a, 13b, 13c, 13d, 13e, 13f) extending in a first, a second and a third direction (D 1, D 2, D 3) being perpendicular to each other, wherein an extension of said reinforcement structure (13a, 13b, 13c, 13d, 13e, 13f) is at least 5 times larger in said first and second directions (D 1, D 2) than in said third direction (D 3), wherein said vehicle power source arrangement comprises at least one lateral wall (17a, 17b) extending along a lateral side of said vehicle power source and at least one cross member (20a, 20b, 20c, 20d) extending across said vehicle power source or along a front side or a rear side thereof, characterized in that said reinforcement structure (13a, 13b, 13c, 13d, 13e, 13f) has a tapered, triangular shape as seen in a plane spanned by said first and second directions (D 1, D 2), wherein said reinforcement structure comprises, or is constituted by at least one strut extending between said cross member (20a, 20b, 20c, 20d) and said lateral wall (17a, 17b), the at least one strut extending in parallel with the longest side of the triangular shape of the reinforcement structure. - a vehicle power source, and - at least one reinforcement structure (13a, 13b, 13c, 13d, 13e, 13f) said reinforcement structure (13a, 13b, 13c, 13d, 13e, 13f) extending in a first, a second and a third direction (D 1, D 2, D 3) being perpendicular to each other, wherein an extension of said reinforcement structure (13a, 13b, 13c, 13d, 13e, 13f) is at least 5 times larger in said first and second directions (D 1, D 2) than in said third direction (D 3), wherein said vehicle power source arrangement comprises at least one lateral wall (17a, 17b) extending along a lateral side of said vehicle power source and at least one cross member (20a, 20b, 20c, 20d) extending across said vehicle power source or along a front side or a rear side thereof, characterized in that said reinforcement structure (13a, 13b, 13c, 13d, 13e, 13f) has a tapered, triangular shape as seen in a plane spanned by said first and second directions (D 1, D 2), wherein said reinforcement structure comprises, or is constituted by at least one strut extending between said cross member (20a, 20b, 20c, 20d) and said lateral wall (17a, 17b), the at least one strut extending in parallel with the longest side of the triangular shape of the reinforcement structure. said reinforcement structure (13a, 13b, 13c, 13d, 13e, 13f) extending in a first, a second and a third direction (D 1, D 2, D 3) being perpendicular to each other, wherein an extension of said reinforcement structure (13a, 13b, 13c, 13d, 13e, 13f) is at least 5 times larger in said first and second directions (D 1, D 2) than in said third direction (D 3), wherein said vehicle power source arrangement comprises at least one lateral wall (17a, 17b) extending along a lateral side of said vehicle power source and at least one cross member (20a, 20b, 20c, 20d) extending across said vehicle power source or along a front side or a rear side thereof, characterized in that said reinforcement structure (13a, 13b, 13c, 13d, 13e, 13f) has a tapered, triangular shape as seen in a plane spanned by said first and second directions (D 1, D 2), wherein said reinforcement structure comprises, or is constituted by at least one strut extending between said cross member (20a, 20b, 20c, 20d) and said lateral wall (17a, 17b), the at least one strut extending in parallel with the longest side of the triangular shape of the reinforcement structure.