This article describes a new design for wireless power transfer in autonomous underwater robots. The aim is to propose a solution for battery charging by taking into account the morphological and dimensional constraints of robots requiring small and low-weight internal modules. An innovative design is presented for inductive power transfer suitable for a wide range of applications. The system is conceptually equivalent to a transformer in which the core can be separated into two parts during operation, one for each coil. Inductive power transfer is selected to have a system to easily and reliably charge different kinds of underwater robots. The secondary coil and its magnetic core are designed to be placed inside a bioinspired robot; the weight, dimensions, and power output for battery charging are optimized. The shape of the secondary magnetic core section is hollow to house the control electronics and sensors. The primary coil is the power inductor, which is placed in a docking unit outside the robot. Experimental results are also reported.