This paper presents a novel control strategy for small-scale photovoltaic inverters aimed at introducing synthetic inertia on the grid side. With the increasing penetration of renewable energy sources and the corresponding decline in conventional synchronous generator participation, grid stability may be compromised, since photovoltaic inverters inherently lack inertia. To address this issue, a model based on DC bus current control is proposed, integrating a two-stage single-phase photovoltaic inverter with a bidirectional converter connected to a battery bank. When connected to the grid, this system acts as a source of synthetic inertia by using battery charge and discharge to smooth power transitions and enhance grid stability. The model is grounded in the Swing Equation of synchronous generators, adapted for photovoltaic inverters. The proposed strategy aims to replicate the inertial response of conventional generators, reducing oscillations and improving the system’s dynamic behavior. Simulations carried out on a 3 kW single-phase inverter demonstrate that the method increases the response time to power variations and ensures smoother transitions. The results indicate that this approach could be a promising solution to expand the share of renewable energy sources in the global energy mix without compromising grid stability.