Method of controlling a power transfer system and power transfer system

A power transfer system, including a power transfer device and at least one portable device, for wireless charging of a battery power source of said portable device comprising:

• a first controller for establishing said data communication link between said power transfer device and said portable device, and for requesting said portable device to transmit an identification information via said data communication link to said power transfer device, the first controller further having a detector for detecting whether said identification information is received from said portable device, and the controller setting a charging power to be transferred to said portable device, said charging power not exceeding a first predetermined value, when said identification information is not received, and
• at least one of first coils connected to said first controller of said power transfer device and as well as a second controller connected to a second coil of said portable device for establishing a power transfer link and transferring said charging power not exceeding said first predetermined value to said portable device.