Devices, methods, and systems for interconnecting all of the battery cells in a battery module from a single side of the battery cell and module are provided. The cell busbar system comprises a number of thin formed strips arranged to interconnect individual battery cells in a row together in series and each row in parallel along a length of the battery module. In particular, the cell busbar system may include two high voltage, or edge, strips and a number of cell-to-cell, or internal, strips electrically interconnected to the edge strips. All of the battery cells in the battery module may be oriented such that all of the positive terminals are facing the same direction. The interconnections between series-connected rows of cells, and parallel rows of series-connected rows, may all be made in substantially the same plane on a single side of the battery module.