During standard cyclic voltammetry (CV) measurements of Li plating/stripping in a three-electrode Swagelok cell, unusually high residual currents were observed, exceeding typical solid electrolyte interphase and double-layer contributions. Systematic investigation revealed that electrolyte leakage and unintended polarization of cell components, such as the stainless steel working electrode plunger, increased the effective electrode surface area and amplified capacitive effects. The effects of cell design, electrolyte volume and concentration, and working electrode surface roughness on capacitive currents were investigated. Optimizing the cell configuration and controlling the substrate surface significantly reduced residual currents, resulting in increased Coulombic efficiency and improved measurement reproducibility. Comparing CV with galvanostatic cycling with potential limitation further revealed intrinsic differences between the protocols, underscoring the impact of experimental conditions on observed electrochemical behavior. The findings provide a cautionary guide for the electrochemical research community, highlighting the critical role of cell design in ensuring reliable and interpretable measurements.