Self-winding power generating device, system, and method are disclosed. The device includes a mechanical winding knob for receiving mechanical energy from a downhole environment, a gear train including a plurality of gears engaged with each other, wherein a first gear in the gear train is operatively connected to the mechanical winding knob, and configured to receive mechanical energy from the mechanical winding knob and transfer the mechanical energy to a second gear in the gear train, a spiral spring attached to one of the gears in the gear train, the spiral spring configured to self-wind and store the mechanical energy upon receiving the mechanical energy from the first gear, and a power generation unit configured to receive the mechanical energy from a last of the plurality of gears and convert the mechanical energy into electrical energy.