A multi-battery pack (1000, 2000) comprising: a plurality of stacked battery packs; and a plurality of long bolts configured to couple the plurality of battery packs to each other and to fix the plurality of battery packs to a device, wherein each of the battery packs comprises a plurality of battery cells and a case configured to receive the plurality of battery cells therein, wherein the case comprises: a case frame defining a space configured to receive the battery cells therein, the case frame being provided at an outside thereof with a plurality of through-holes through which the long bolts are inserted; a lower cover coupled to a lower part of the case frame; and an upper cover coupled to an upper part of the case frame, and wherein the upper cover comprises a circular first fastening hole and a second fastening hole having one side open in a C-shape, the first fastening hole and the second fastening hole being configured to allow the long bolts to be fastened therethrough, wherein a hollow cylindrical bushing configured to prevent deformation of the case due to fastening of the long bolts is inserted into each of the through-holes, and wherein the bushing protrudes and extends upward from the upper cover to be inserted into the lower cover of the battery pack stacked thereon. a plurality of stacked battery packs; and a plurality of long bolts configured to couple the plurality of battery packs to each other and to fix the plurality of battery packs to a device, wherein each of the battery packs comprises a plurality of battery cells and a case configured to receive the plurality of battery cells therein, wherein the case comprises: a case frame defining a space configured to receive the battery cells therein, the case frame being provided at an outside thereof with a plurality of through-holes through which the long bolts are inserted; a lower cover coupled to a lower part of the case frame; and an upper cover coupled to an upper part of the case frame, and wherein the upper cover comprises a circular first fastening hole and a second fastening hole having one side open in a C-shape, the first fastening hole and the second fastening hole being configured to allow the long bolts to be fastened therethrough, wherein a hollow cylindrical bushing configured to prevent deformation of the case due to fastening of the long bolts is inserted into each of the through-holes, and wherein the bushing protrudes and extends upward from the upper cover to be inserted into the lower cover of the battery pack stacked thereon. a case frame defining a space configured to receive the battery cells therein, the case frame being provided at an outside thereof with a plurality of through-holes through which the long bolts are inserted; a lower cover coupled to a lower part of the case frame; and an upper cover coupled to an upper part of the case frame, and wherein the upper cover comprises a circular first fastening hole and a second fastening hole having one side open in a C-shape, the first fastening hole and the second fastening hole being configured to allow the long bolts to be fastened therethrough, wherein a hollow cylindrical bushing configured to prevent deformation of the case due to fastening of the long bolts is inserted into each of the through-holes, and wherein the bushing protrudes and extends upward from the upper cover to be inserted into the lower cover of the battery pack stacked thereon.