Patent ID: 8115447

Claim:
A battery pack rechargeable by a magnetic induction effect, the battery pack comprising: a secondary coil to be electromagnetically coupled to a primary coil incorporated in a battery charger; a secondary battery rechargeable by electric power induced to the secondary coil; and a spacer for covering a surface of the secondary battery, the spacer being made of a non-magnetic material, wherein the secondary battery is in a form of a thin battery having a larger width than a thickness, and two opposing surfaces composed of a first flat surface and a second flat surface in the thickness direction of the battery, wherein the secondary coil is in a form of a planar coil layered above the first flat surface of the thin battery, wherein the spacer is layered above the first flat surface of the thin battery, and the spacer is formed in a flat form and defines a positioning area, the positioning area being formed as a fitting-in recess in the spacer or as a hole in the spacer, wherein the secondary coil is positioned in the positioning area of the spacer to be surrounded by a peripheral area of the spacer, the peripheral area of the spacer including a top surface and a bottom surface, the bottom surface facing the first flat surface of the thin battery, and wherein an exterior side surface of the secondary coil is flush or coplanar with the top surface of the peripheral area of the spacer.