A charging device includes a body having a rechargeable energy storage device and a housing, an interface pivotally coupled to the housing, the interface including a first conductor and a second conductor and configured to transmit power between the rechargeable energy storage device and a device connected to the interface, a first rigid post, a first pin, a first compressible element positioned to press the first pin against the first rigid post, a second rigid post, a second pin, and a second compressible element positioned to press the second pin against the second rigid post. The interface is configured to pivot about an axis defined by the first pin and the second pin.