The invention relates to a multi-stage charging device for a battery of a battery operated electrical motor. The multistage charging device comprises a buck converter, an intermediate circuit and a boost converter in order to generate a suitable direct charging current from a (one or three-phase) alternating current provided by a power connection. According to the invention, components of the electrical drive are used for the boost converter and the intermediate circuit: the electrical motor functions as an intermediate circuit and the drive converter functions as a boost converter. According to the invention, the coupling of the electrical motor to the network-side buck converter occurs so that at least half the charging current flows through at least one of the at least three coils of the electrical drive. The invention further relates to a corresponding method and to a corresponding use of the drive components.