The disclosure presents a method for starting up a battery system having a battery, a DC voltage intermediate circuit which is connected to the battery, and a drive system which is connected to the DC voltage intermediate circuit. The battery has a large number of battery modules which are connected in series and which each comprise a coupling unit and at least one battery cell which is connected between a first input and a second input of the coupling unit. The method comprises a step for decoupling the battery cells of all of the battery modules which are connected in series by outputting a corresponding control signal to the coupling units of the battery modules which are connected in series. All of the battery modules which are connected in series are then bridged at the output end, and therefore an output voltage of the battery is zero.