An example system is disclosed for thermal management of batteries. The system may include a cell bank that includes first and second cell frame sections, a heat bus, and thermal interface material. The first and second cell frame sections may define opposite surfaces of the cell bank. Each cell frame section may include recesses to align battery cells for welding and provided conductive connections between the cells to create a string of cells with a combined power output. Each recess may include a divider between the battery cells to preload the cells against a thermal junction during assembly. The heat bus may be provided between the cell frame sections. The heat bus may include heat pipes that extend between the battery cells and across the cell frame sections. The thermal interface material may be positioned to transfer heat from the cells to the heat pipes at their thermal junction.