An efficient battery powered oscillating mobile comprises of a mobile, elastic cord, free standing module assembly, plurality of keeper fasteners, and external rigid anchor point. The mobile comprises of an outer shell, which comprises of a printed circuit board assembly, hole, tab, and cord. The printed circuit board assembly comprises of a printed circuit board, motor, motor shaft, metal arm, and cross beam. Each keeper fastener comprises of keeper fingers, blade screwdriver slot, keeper head, and keeper shaft. The free standing module comprises of a power source assembly, housing mechanism, motor assembly, catch, catch slot, plurality of slots, sliding guide, printed circuit board assembly, electrical contact pin, plurality of retainer holes, snap locks, switch spring system, cord adaptor, coin cells, and keeper spring.