Patent ID: 9018900
Filing Date: 2015-04-28
Classification: H02J

Abstract:
1. A battery pack to be connected to the body of a battery powered device to supply power to drive the battery powered device which is capable of displaying remaining battery capacity, the battery pack comprising: a rechargeable battery cell; a receiving coil that can magnetically couple with a transmitting coil housed in a charging pad; a charging current path formed by a charging circuit that converts power received by the receiving coil from the transmitting coil to charge the rechargeable battery cell; a connection decision section to determine whether the battery pack is alone or connected with the body of the battery powered device; a current path switch connected with the charging circuit and controlled based on decisions by the connection decision section to close when the battery pack is alone and to open when the battery pack is connected with the body of the battery powered device; a contactless charging circuit that rectifies power induced in the receiving coil; and a battery pack control section that includes the connection decision section, wherein the battery pack control section is configured to judge whether or not the body of the battery powered device is connected based on a voltage rectified by the contactless charging circuit.