Abstract Many studies on solid-liquid triboelectricity have used electrons in water as a means to generate electricity. However, for such applications researchers have utilized the same mechanism as that formalized for solid-solid triboelectricity. In this paper, a direct charge control method for generating liquid-solid triboelectricity is proposed. This mechanism suggests a new method for solid-liquid state triboelectricity using the inherent properties of a liquid. The proposed direct charge control strategy employs a liquid-solid triboelectricity to separate positive and negative charges in water. In the case of indirect charge control, external electrons from the ground or an electrode are used and thus, suitable electrical parts are needed for rectification. This can reduce the usable power. In contrast, direct charge control does not require additional electrical components for rectification, and available power is conserved. Upon overcoming certain limitations, normal operation of a system without rectification was realized, and a capacitor (100 μF) was charged to over 14 mV. In the relationship between the streaming electrification equation and the obtained results, the electronegativity of the material, tube length, and number of tubes affect the charging voltage. Here, the charged voltage increased above 100 mV as the tube length was increased. Such finding indicates that the output of direct charge control can be enhanced by various factors, thereby pioneering new areas for solid-liquid triboelectricity.