BATTERY PACK INCORPORATING BATTERY MODULE AND RIGID BEAM AND ADOPTING REVERSE ASSEMBLING

Disclosed is a battery pack, which includes a plurality of battery modules and a pack case in which the battery modules are fixedly installed, the battery case includes a pack tray located at a lower portion of the battery modules, and a pack cover coupled with the pack tray to cover the battery modules, and each of the battery modules is fixedly coupled to the pack cover and includes battery cells arranged in one direction, a module case for accommodating the battery cells in an inner space thereof, and a rigid beam disposed between the battery cells inside the module case.