Disclosed herein is a battery 
cartridge for middle- or large-sized battery packs, which has one or more unit cells mounted therein. The battery 
cartridge is generally constructed in a plate-shaped structure for easy stacking, and connecting members for 
electrical connection between cartridges are constructed in a 
coupling structure in which the connecting members are coupled with each other during the stacking of the cartridges. When a plurality of cartridges are stacked one on another so as to construct a middle- or large-sized 
battery pack, the mechanical 
coupling between the cartridges is accomplished, and, at the same time, the 
electrical connection between the cartridges is also accomplished, whereby the 
assembly of the cartridges is easily accomplished, and the risk of short circuits is prevented during the 
assembly or the use of the cartridges. Furthermore, a middle- or large-sized 
battery pack manufactured using the battery 
cartridge according to the present invention has a stable compact structure. Consequently, the middle- or large-sized 
battery pack is preferably used as a power source for electric vehicles or 
hybrid electric vehicles.