In this letter, we have proposed a self-powered accelerometer system using circular hole-based piezoelectric energy harvester. The proposed circular hole-based harvester exhibits an open circuit voltage of 33 V pp , which is 13.8% greater and resonant frequency of 24 Hz, which is 7.7% lower than the traditional harvester without hole. The performance metrics of the proposed harvester such as stress, strain, resonance frequency, voltage, and power, are thoroughly analyzed. The extracted energy by the proposed energy harvester from a vibration source is around 673 mJ with an average power of 170 μW, which is approximately 89% more than the conventional one. Performance of the harvester is also investigated by integrating the harvester with two nonlinear switching circuit topologies and a low power voltage regulator H T 7333. It is observed from experimental studies that H T 7333-based configurations works more efficiently than the previously reported configurations due to their low power consumptions, which makes it a potential energy management unit in self-powered systems. The energy harvested and energy consumed by the individual units are analyzed extensively and a commercial accelerometer ADX L − 335 is powered and tested with the H T 7333 configurations. Finally, the proposed prototype is also mounted on a motor vehicle, tested, and validated experimentally. Keywords— Capacitive sensor system, Interfacing circuit, signal conditioning, Calibration voltage.