A battery unit includes multiple cell modules which are interconnected. The cell modules respectively include multiple battery cells. Local cell module control units are associated with the cell modules. The cell module control units are configured in such a way that they control and/or monitor the cell modules. The cell module control units are applied to at least one flat conductor sheet. The flat conductor sheet has plugs which are plugged into mating plugs of the cell modules. There is also described a wiring unit for a battery unit.