Abstract: A battery pack includes a housing including a side wall. The side wall has a plurality of through holes. A plurality of battery modules are accommodated inside the housing; a plurality of fastener devices securing the battery modules to the side wall, each fastener device passing through a respective through hole and sealingly closing the through hole; and a cover plate sealingly joined to the side wall. The fastener devices are positioned outside the cover plate.

Abstract: A battery pack system includes a first battery pack including a first casing and a plurality of battery modules arranged inside the first casing; a second battery pack including a second casing and a plurality of battery modules arranged inside the second casing; and a coupling including a first coupling member fixed to the first casing, and a second coupling member fixed to the second casing, the first coupling member being configured to mate with the second coupling member; wherein the coupling is configured to transfer torques and translational forces.