We designed and implemented a hand-shaken energy harvesting charger capable of storing mechanical energy in a battery bank and supplying regulated power to a USB output with the intent to charge a cellular device. The device is a renewable source of energy which can be utilized in off-grid and emergency situations as well as in learning environments. The goal of this project is to lay the groundwork for developing a low-cost system capable of producing power to a mobile device without the need for traditional power sources, while providing visibility to the user of the core components of the energy generation process. The device demonstrates the integration of energy harvesting, storing, and delivering to a load. Each aspect must be done with a level of safety and precision to ensure that the user can use the device without issues or safety concerns. The project highlights the practical challenges that engineering design requires, such as integrating multiple stages of power together as well as working with unstable power sources and how to regulate them to be useful. The device weighs less than 10 pounds, is one foot long with room for refinement within specifications and can deliver 5V DC output through the USB port to charge a mobile device. Under multiple tests on an Apple AirPods Pro, an average of 1.5% was charged per minute with the Nickel-Metal Hydride batteries directly connected through the USB port. The voltage generated from the AC shaking input is roughly 18 V peak to peak with minimal load, giving an amplitude of 9V, just above the goal of 8V. A current goal is to measure the exact values of charge provided to the onboard battery bank to calculate the efficiency of shaking output.
