Unit cell pack

A unit cell pack, comprising:

• a first battery module comprising battery cartridges that are sequentially stacked, a plurality of batteries wherein two batteries are seated on an upper surface of each of the battery cartridges, electrode connection members respectively positioned on both sides of the battery cartridges, and a battery cover covering the battery cartridges, the plurality of batteries, and the electrode connection members;
• a second battery module being adjacent to the first battery module and including same constituent elements as the first battery module;
• a battery housing surrounding the first battery module and the second battery module, and including air inflow window covers and air outflow window covers facing each other;
• and
• a fan duct disposed on the air outflow window covers of the battery housing, wherein
• the two batteries on the upper surface of each of the battery cartridges are electrically connected in parallel,
• the battery cartridges are electrically connected in series through the electrode connection members,
• a lower surface of each of the battery cartridges defines air guide grooves with respect to each other,
• the air guide grooves are aligned with the air inflow window covers and the air outflow window covers on one of the first battery module and the second battery module, forming straight air passages,
• each of the battery cartridges comprises two battery seating portions, bus bars positioned between the battery seating portions, and a cartridge coupling ring positioned between the bus bars to connect the battery seating portions, and
• the cartridge coupling ring comprises a through hole passing through a central region, and a fitting member protruding from an inlet of one side portion of the through hole.