A 3D-printed multicoupled piston-type cylindrical triboelectric nanogenerator (MPC-TENG) that utilizes contact-separation and lateral-sliding operational modes to harvest rotational motion and convert it into electricity was proposed. The electrical performances of the fabricated four similar piston-type cylindrical TENGs (PC-TENGs) were systematically investigated. TENGs in general produce electricity in an alternating-signal form which may not be used to directly power electronic devices. Therefore, all the individual PC-TENGs were connected with a simple external filter circuit to obtain direct current (DC) electrical output, and further, they were parallelly connected to increase the overall electrical output from the MPC-TENG. The MPC-TENG consists of four PC-TENGs and produces a DC electrical output of ~40 V and ~12.5 μA at 380 rpm. Furthermore, the MPC-TENG was attached to wind cups to harvest wind energy and a Pilton wheel to harvest hydrokinetic energy, respectively. The harvested energy was stored in energy storage devices to power various small-scale electronic gadgets. Furthermore, a real-time self-sustaining alarm combined with the MPC-TENG was demonstrated to detect unauthorized human/wild animal entry into a protected region. This work also shows that the DC electrical signals from the proposed MPC-TENG can be further increased by combining more PC-TENG devices.