A lithium-ion battery module , comprising: - a terminal block assembly that defines a major terminal of the battery module and that is secured to a polymer housing of the battery module , the terminal block assembly comprising: - a terminal post having a post portion and a base portion that extends outward from a central axis of the post portion ; - a bus bar physically coupled to the base portion of the terminal post without welding to form an electrical assembly, wherein the bus bar is electrically coupled to a first plurality of cell terminals of a plurality of lithium-ion battery cells disposed within a water-tight interior volume of the polymer housing , and wherein the bus bar includes a U-shaped trough near the terminal post , and a hairpin bend disposed adjacent to the trough , wherein the hairpin bend extends in a direction opposite the trough ; and - a polymer portion having a substantially rectangular cross-section and overmolding at least the trough and the hairpin bend of the bus bar such that, when overmolded, the trough forms a drainage channel near the terminal post , and wherein the trough is disposed near an interface between the polymer portion and an exposed base of the bus bar surrounding the terminal post , wherein the exposed base of the bus bar is not overmolded by the polymer portion . - a terminal block assembly that defines a major terminal of the battery module and that is secured to a polymer housing of the battery module , the terminal block assembly comprising: - a terminal post having a post portion and a base portion that extends outward from a central axis of the post portion ; - a bus bar physically coupled to the base portion of the terminal post without welding to form an electrical assembly, wherein the bus bar is electrically coupled to a first plurality of cell terminals of a plurality of lithium-ion battery cells disposed within a water-tight interior volume of the polymer housing , and wherein the bus bar includes a U-shaped trough near the terminal post , and a hairpin bend disposed adjacent to the trough , wherein the hairpin bend extends in a direction opposite the trough ; and - a polymer portion having a substantially rectangular cross-section and overmolding at least the trough and the hairpin bend of the bus bar such that, when overmolded, the trough forms a drainage channel near the terminal post , and wherein the trough is disposed near an interface between the polymer portion and an exposed base of the bus bar surrounding the terminal post , wherein the exposed base of the bus bar is not overmolded by the polymer portion . - a terminal post having a post portion and a base portion that extends outward from a central axis of the post portion ; - a bus bar physically coupled to the base portion of the terminal post without welding to form an electrical assembly, wherein the bus bar is electrically coupled to a first plurality of cell terminals of a plurality of lithium-ion battery cells disposed within a water-tight interior volume of the polymer housing , and wherein the bus bar includes a U-shaped trough near the terminal post , and a hairpin bend disposed adjacent to the trough , wherein the hairpin bend extends in a direction opposite the trough ; and - a polymer portion having a substantially rectangular cross-section and overmolding at least the trough and the hairpin bend of the bus bar such that, when overmolded, the trough forms a drainage channel near the terminal post , and wherein the trough is disposed near an interface between the polymer portion and an exposed base of the bus bar surrounding the terminal post , wherein the exposed base of the bus bar is not overmolded by the polymer portion . <EOS>