Battery module having electrolytic solution leakage detection function and battery pack including the same

A battery module comprising:

• a module case comprising a bottom plate, a side plate, and a top plate;
• a plurality of battery cells received in the module case;
• and
• a plurality of busbars configured to connect the plurality of battery cells to each other in series or in parallel,
• wherein at least one of the plurality of busbars includes an extension portion protruding from a lower end of a busbar body by a predetermined length toward the bottom plate of the module case, a bottom edge of each extension portion being closer to the bottom plate than a bottom edge of the busbars of the plurality of busbars that are not the at least one of the plurality of busbars including the extension portion.