Commercial AWEs are commonly manufactured with a bipolar stack configuration, where the cells are electrically connected in series. The outer electrodes, known as endplates, are supplied with the power supply, while the intermediate electrodes, known as bipolar electrodes, act as an anode on one side and a cathode on the other. However, one inherent limitation of this configuration that restricts further scaling of AWE systems is stray current, driven by the high potential difference between cells, which causes ionic current to flow through channels and manifolds. Stray currents are electrical currents that deviate from the intended electrolytic pathway within the stack's electrical system and instead flow through the channels and manifolds. This geometric configuration leads to nonuniform current-potential distributions, resulting in decreased current efficiency. This paper presents a reliable numerical method, based on the finite element formulation, to investigate the hydrodynamic and electrical performance of the stack. A three-dimensional (3D) multiphysics model of a 12-cell non-zero gap AWE stack has been built up in COMSOL, incorporating an electrochemical model and an Euler-Eulerian k-epsilon turbulence model. Subsequently, the influence of different stack voltages on stray currents and gas volume fraction was examined. The numerical results showed that the share of stray currents decreased and the effective current increased at higher stack voltages, resulting in higher Faradaic efficiency. Increasing the voltage (current) increases gas production, thereby increasing the electrical resistance of channels and manifolds. This increased resistance will reduce the stray current, thereby enhancing the current efficiency of the stack