Battery charger cradle

A battery charger cradle designed to be used with a battery built-in device having an electromagnetically coupled induction coil incorporated in the battery built-in device and a battery rechargeable with a power induced by the induction coil, the battery charger cradle comprising:

• a primary coil connected to an AC power source for inducing electromotive force to the induction coil;
• a casing containing the primary coil and having a top plate on the top of which the battery built-in device is to be placed;
• a movement mechanism contained in the casing for moving the primary coil along an inner surface of the top plate;
• and
• a position detection controller detecting a position of the battery built-in device placed on the top plate and controlling the movement mechanism to bring the primary coil closer to the induction coil contained in the battery built-in device,
• wherein, when the battery built-in device is placed on the top plate of the casing, the position detection controller detects the position of the battery built-in device, the position detection controller controls the movement mechanism, and the movement mechanism moves the primary coil along the top plate to bring the primary coil closer to the induction coil contained in the battery built-in device.