A battery module , comprising: - a housing , comprising a top wall, a bottom wall, a back wall extending between the top wall and the bottom wall, and an inside positioned between the top wall and the bottom wall; - electrochemical cells disposed in one or more stacks in the inside of the housing , wherein the electrochemical cells are spaced apart from each other to enable an airflow to flow between the electrochemical cells , wherein the one or more stacks of the electrochemical cells extend upwardly from the bottom wall of the housing to the top wall of the housing , wherein base ends of the electrochemical cells are disposed proximate to the back wall of the housing and terminal ends of the electrochemical cells are disposed proximate to the front wall of the housing , wherein broad faces of the electrochemical cells extend between the base ends and the terminal ends of the electrochemical cells and are stacked proximate to each other; - a fan disposed on an outside of the top wall of the housing ; - a hood disposed over the fan and configured to contact the housing to direct the airflow from the fan into the inside of the housing through an entry point disposed on the back wall of the housing , wherein the entry point comprises slotted openings disposed through the back wall of the housing ; - a vent fluidly coupling the inside of the housing to the outside of the housing and configured to vent the airflow from the inside of the housing to the outside of the housing ; and - flow guide features configured to guide the airflow from the entry point along the electrochemical cells , wherein the hood comprises an extension configured to extend from the top wall of the housing over the back wall of the housing , wherein the extension comprises outer ridges configured to seal against the back wall of the housing around the slotted openings , and wherein the extension is configured to guide the airflow from the fan on the outside of the top wall of the housing to the back wall of the housing and into the slotted openings disposed through the back wall of the housing . - a housing , comprising a top wall, a bottom wall, a back wall extending between the top wall and the bottom wall, and an inside positioned between the top wall and the bottom wall; - electrochemical cells disposed in one or more stacks in the inside of the housing , wherein the electrochemical cells are spaced apart from each other to enable an airflow to flow between the electrochemical cells , wherein the one or more stacks of the electrochemical cells extend upwardly from the bottom wall of the housing to the top wall of the housing , wherein base ends of the electrochemical cells are disposed proximate to the back wall of the housing and terminal ends of the electrochemical cells are disposed proximate to the front wall of the housing , wherein broad faces of the electrochemical cells extend between the base ends and the terminal ends of the electrochemical cells and are stacked proximate to each other; - a fan disposed on an outside of the top wall of the housing ; - a hood disposed over the fan and configured to contact the housing to direct the airflow from the fan into the inside of the housing through an entry point disposed on the back wall of the housing , wherein the entry point comprises slotted openings disposed through the back wall of the housing ; - a vent fluidly coupling the inside of the housing to the outside of the housing and configured to vent the airflow from the inside of the housing to the outside of the housing ; and - flow guide features configured to guide the airflow from the entry point along the electrochemical cells , <EOS>