An EAS security tag for providing both EAS and battery recharging features within one tag. The tag includes a rechargeable battery and an antenna having a magnetic core and at least one coil winding disposed around at least a portion of the core. The antenna supplies a voltage corresponding to a first frequency or a second frequency when placed within a magnetic field. The tag also includes an EAS circuit having a resonant frequency corresponding to the first frequency, and an energy harvesting circuit having a resonant frequency corresponding to the second frequency, where the battery recharging circuit recharges the rechargeable battery. Depending upon the magnetic field that the tag is exposed to, either the EAS circuit is enabled thus allowing for EAS detection or the energy harvesting circuit is enabled allowing for the battery to be recharged.