A computer comprises a computer chassis, a communication connector provided on a surface of the chassis to mate the computer with a docking station, and first and second battery packs. The first battery pack is adapted to mate to the surface of the chassis. The first battery pack has a shape that defines a volume in which at least a portion of the docking station can be inserted to mate to the communication connector. Further, the first battery pack has a first battery pack connector. The second battery pack has a shape that corresponds to the volume defined by the first battery pack's shape. The second battery pack has a second battery connector that mates to the first battery connector when the second battery pack is mated to the first battery pack.