An electrical interface (125, 215) interconnects an electrical device (110) with a removable battery package (120). The electrical interface (125, 215) includes deflectable cantilever contacts (260) that are preferably located within the battery package (120). Each cantilever contact (260) has a portion (261) anchored to a substrate (250), and a deflectable portion (262) biased against a housing member (240), which deflectable portion (262) is externally accessible via a slot (248) within the housing member (240). Preferably, the cantilever contacts (260) are located within a recessed area (245) on an interior surface (241) of the housing member (240). A corresponding projection (346) extends externally on the housing member (240). The external projection (346) facilitates a plug and socket arrangement for mating the battery (120) to the electrical device (110). The substrate (250) is preferably formed from flexible film material and is structurally supported by a backer (270) attached to the housing member (240).