An auxiliary device including an energy harvester and an electronic device including the auxiliary device are provided. The auxiliary device includes: a housing; a storage module which is moveable within the housing; and at least one piezoelectric transducer which disposed in the housing, such that a motion of the storage module causes a deformation of the piezoelectric transducer, thus generating electric energy. An end of the piezoelectric transducer may be fixedly connected to the storage module.