A battery pack, comprising: a first battery module having first and second battery frame assemblies (90, 92) and first and second battery cells (94, 96); the first battery frame assembly having a first plastic frame member, a first busbar, and a first voltage sensing member; the second battery frame assembly being coupled to the first battery frame assembly such that the first and second battery cells (94, 96) are disposed between the first and second battery frame assemblies (90, 92); and the first plastic frame member having a first rectangular ring-shaped body with first, second, third and fourth side walls (150, 152, 154, 156) defining a first central space; the first and second side walls (150, 152) of the first rectangular ring-shaped body extending substantially perpendicular to one another, the third and fourth side walls (154, 156) of the first rectangular ring-shaped body being coupled to the first and second side walls (150, 152) of the first rectangular ring-shaped body and extending substantially perpendicular to one another; characterized in that the battery pack further comprises a first thermally conductive plate, the first thermally conductive plate being coupled to the first, second, third and fourth side walls (150, 152, 154, 156) of the first rectangular ring-shaped body and being adapted to enclose the first central space, a first plate portion of the first thermally conductive plate being disposed on an outer surface of the second side wall of the first rectangular ring-shaped body; the first busbar having a first post and a first conductive body coupled to the first post, the first post extending outwardly from the first side wall of the first rectangular ring-shaped body; the first conductive body extending through the third side wall of the first rectangular ring-shaped body and outwardly therefrom; the first voltage sensing member having a first sensing post and a first sensing body coupled to the first sensing post, the first sensing post extending outwardly from the first side wall of the first rectangular ring-shaped body; the first sensing body extending through the fourth side wall of the first rectangular ring-shaped body and outwardly therefrom; the first battery cell having a first body portion and first and second electrical terminals (442, 444) extending outwardly from first and second ends, respectively, of the first body portion; the first electrical terminal of the first battery cell being coupled to the first conductive body of the first busbar; the second electrical terminal of the first battery cell being coupled to the first sensing body of the first voltage sensing member; and the second battery cell having a second body portion and first and second electrical terminals (452, 454) extending outwardly from first and second ends, respectively, of the second body portion; the second electrical terminal of the second battery cell being coupled to the second electrical terminal of the first battery cell. a first battery module having first and second battery frame assemblies (90, 92) and first and second battery cells (94, 96); the first battery frame assembly having a first plastic frame member, a first busbar, and a first voltage sensing member; the second battery frame assembly being coupled to the first battery frame assembly such that the first and second battery cells (94, 96) are disposed between the first and second battery frame assemblies (90, 92); and the first plastic frame member having a first rectangular ring-shaped body with first, second, third and fourth side walls (150, 152, 154, 156) defining a first central space; the first and second side walls (150, 152) of the first rectangular ring-shaped body extending substantially perpendicular to one another, the third and fourth side walls (154, 156) of the first rectangular ring-shaped body being coupled to the first and second side walls (150, 152) of the first rectangular ring-shaped body and extending substantially perpendicular to one another;