BATTERY PACK

The present technology relates to a battery pack. More specifically, the battery pack of the present technology includes pack case that includes a module area in which the battery modules are mounted, and the pack case including a base plate in the form of a hollow shape and having a plurality of space parts formed therein to support a lower part of a battery module and in which coolant is stored; sidewalls coupled to a rim of the base plate; and a separation wall coupled to the base plate to separate the battery modules from each other; the separation wall including: a main separation wall extended and formed across the centered part of the pack case, the base plate enable to flow in out and coupled to the space part and an inlet and an outlet at each end connecting the space parts with each other located between a pair of adjacent space parts, and further includes a flow path part including a plurality of cooling flow paths to connect the space parts each other.