Abstract: A power supplying device including a body portion having an inner end with a vertical wall on which are mounted a pair of electrodes, the vertical wall having a bottom extending outwardly to form a battery seat, the battery seat having a bed provided with two opposite grooves one at each side thereof and a spring-loaded retainer member close to an outer edge of the battery bed, a dry battery pack including a housing and a cover, the housing being for receiving dry batteries and provided at one end with two openings for mounting a pair of electrodes, the housing having a bottom formed with two flanges one at each side thereof and a slot close to another end of the housing, and a rechargeable battery pack including a casing and a covering plate, the casing being for receiving rechargeable batteries, the covering plate having a cavity adapted to receive the retainer member, the casing having a bottom formed with two flanges one at each side thereof.