Some applications require an energy transfer without contacts and wires. The mutual inductive effects between two coils allow to transfer energy to an electronic consumer through an air gap. This paper presents an analytical model of a coreless transformer used to design a contactless energy transfer from a platform to a notebook battery charger. By defining the geometric parameters of the transformer, the model is able to compute its magnetic parameters. It is then possible to get the electric quantities with a circuit simplification process. In the scope of an industrial project, this study has been successfully applied to a notebook battery charging platform.