The present invention relates to a battery pack including a housing, a latch mechanism, a printed circuit board connected to electrical terminals, and an internal frame. The housing includes a first and second portion. The first portion includes openings that receive the latch mechanism and openings that receive the terminals. The battery pack also includes a latch cover that protects against water infiltrating between the openings and the latch mechanism, and a terminal cover that protects against water infiltrating between the first housing portion and the terminals. Water that enters the battery pack is directed to the bottom of the battery pack. The water is then drained through openings in the lower housing portion. The internal frame includes openings that secure batteries within the lower housing portion with the help of wedges that are positioned in between adjacent rows of batteries.