Wireless power for mobile devices

Wireless power transfer allows a convenient, easy to use battery charging of mobile phones and other mobile devices. No hassle with cables and plugs, just place the device on a pad and that's it. Such a system even has the potential to become a standard charging solution. Where are the limits for such a solution and which are the side conditions to consider? What are the possibilities to realize such a system? To make the whole idea a success, it is definitely necessary to come to widely accepted standard. Therefore, in 2009 the Wireless Power Consortium was founded with meanwhile more than 80 international companies as members. The consortium recently released the first worldwide standard on wireless power for mobile devices of to 5W called "Qi". The contribution presents details of this standard and the rationale behind.