TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Battery Module: The thermal management feature comprises at least one tube having an internal passage for the thermal management fluid to pass through it. The lower portion comprises a heat sink. The heat sink has tapered fins extending away from the electrochemical cells, where the thermal management fluid is configured to pass between the fins. The lower portion comprises a feature configured to divide the flow of the thermal management fluid through the heat sink in a first direction and in a second direction generally opposite the first direction. The battery module comprises a feature configured to change the direction of the flow of the thermal management fluid through the heat sink from the first direction to the second direction. The thermal management feature is configured to route the thermal management fluid through the thermal management feature only in a single direction. The thermal management feature is configured to route the thermal management fluid through the thermal management feature in a first direction and in a second direction generally opposite the first direction. The upper portion of the structure comprises sockets, each socket configured to receive the bottom portion of one of the electrochemical cells. A chamber is formed between the upper portion of the structure and the lower portion of the structure, the chamber configured to receive vented gasses from any of the electrochemical cells. The structure comprises at least one post provided in the chamber and configured to conductively couple the upper portion of the structure to the lower portion of the structure. The battery module further comprises an electrically insulating material provided between the electrochemical cells and the structure. The battery module further comprises at least one panel configured to retain the electrochemical cells to the structure. Preferred Battery System: The battery system further comprises a manifold configured to route the thermal management fluid from a first source to the battery modules.