A wireless charging device includes a plurality of antennas, a plurality of AC/DC converters, and a controller. The antennas receive power, are located at different positions of an electronic device, and are oriented in different directions. The AC/DC converters are connected to respective ones of the antennas and convert AC signals from the antennas to DC signals. The controller measures intensities of the converted signals from the AC/DC converters, compares the intensities, and selects one of the antennas having a greater intensity for charging a battery.