Battery systems and modules having external thermal management systems are provided. In one embodiment, a battery module includes a housing and at least one electrochemical cell disposed within the housing. The battery module also includes a thermal interface having a first side in contact with the at least one electrochemical cell. The battery module also includes a heat sink in contact with a second side of the thermal interface. The thermal interface is adapted to enable heat transfer from the at least one electrochemical cell to the heat sink.