This paper presents a non-model-based control technique for a Hybrid Energy Storage System (HESS). The proposed control law is based on an optimized fuzzy logic approach called the signed-distance or single input fuzzy logic controller (FLC). The developed control technique offers several advantages and features over conventional control laws, including the elimination of the need for an exact mathematical model for controller design, robustness against parameter variation, and high stability in the presence of production or load changes. The concept of the proposed control technique has been experimentally implemented on a MicroLabBox Dspace card and validated on a test bench consisting of a PV system as the main energy source, along with a battery and supercapacitor for energy storage. Theoretical and practical studies demonstrate that satisfactory tracking performance can be achieved with fewer fuzzy rules compared to conventional multi-input fuzzy logic controllers, without the need for additional sensors or knowledge of the system model and parameters.