The need for an initial excitation system (sparetly exciter) in small-scale power generation is crucial, especially in remote or off-grid areas. This research aims to design and develop a direct current (DC) pico-hydro power generation system based on a micro water turbine, which is utilized to charge a battery serving as the initial excitation power source. The system employs a mini water turbine to drive a DC generator, and the output voltage is conditioned through a buckboost converter to match the requirements of a 12 V battery charging system. Experimental results indicate that the system can produce output voltages ranging from 17 V to 32 V and currents between 0.0016 A and 0.0031 A, with turbine rotational speeds between 241 and 470 RPM. The charging process was conducted over a period of 180 minutes, resulting in a State of Charge (SOC) increase from 0% to 100%. These results demonstrate that the system operates stably and efficiently in a slow-charging mode. The developed pico-hydro system has proven to be a viable alternative power source for initial excitation applications and can be implemented in off-grid systems or areas with limited access to conventional electricity. The system’s reliability depends significantly on the stability of water flow and the efficiency of mechanical-to-electrical energy conversion.