Abstract: A pool cleaning robot that may include a housing, a propulsion mechanism configured to propel the pool cleaning robot along an interior surface of a pool; brushes to clean surfaces of the pool during a cleaning cycle, a filtering system, a suction mechanism to draw liquid from the pool through an inlet into the housing and to discharge it from an outlet; and a detachable module that is detachably coupled to the housing, wherein at least one of the following is true—(a) the detachable module is a battery, (b) the detachable module comprises inductive electrical transfer connections, and (c) the detachable module comprises inductive data transfer connections.

Abstract: A method for charging a pool cleaning robot, the method may include positioning a first wireless charging element of a pool cleaning robot within a charging range of a second wireless charging element of a floating unit; wherein the floating unit is electrically and mechanically coupled to an external power source, wherein the positioning comprises moving at least one of the pool cleaning robot and the floating unit; and wirelessly charging, by the second wireless charging element, the first wireless charging element, wherein the charging occurs while maintaining the first wireless charging element within the charging range of the floating unit, despite movements of the floating unit.