To provide a contactless charging 
system that provides superior 
usability and allows for a reduction in 
power consumption and a safety measure, as well as to provide an electronic device, a contactless charger, and a 
battery pack for an electronic device which are used in the 
system.A contactless charging 
system is made up of a 
mobile phone 100 that is an electronic device and a contactless charger 200 that recharges the 
mobile phone 100 in a contactless manner. The 
mobile phone 100 transmits a full charge command indicating completion of charge. Upon 
receipt of the full charge command, the contactless charger 200 shifts to a charge stop state in which charge of the mobile phone 100 is not performed. In the charge stop state, the contactless charger 200 generates a load check 
signal for checking whether or not the mobile phone 100 is placed in the contactless charger 200 in a rechargeable state, and transmits the 
signal. Further, the contactless charger 200 also generates a charge restart check command for checking whether or not the mobile phone 100 requests recharge in a charge stop state, and transmits the command.