This study investigates the impact of the Tesla Wall Connector charging station on the voltage of the distribution system. We adopted an experimental testing approach, observing and recording the effects of an onboard charger on voltage variations at different charging speeds and under different distribution system loads. Experimental results revealed that as the charging speed increases, the voltage of the distribution system changes correspondingly. Under low-load conditions, the impact of the third-generation Tesla Wall Connector on the voltage of the distribution system is relatively small. However, as the load on the distribution system increases, especially when approaching its load limit, high-speed charging of the Tesla Wall Connector Charger leads to a significant drop in the voltage of the distribution system. These findings suggest that to maintain the stability of the distribution system, appropriate power management of the Tesla’s third-generation Wall Connector is necessary, especially under high-load conditions. This study provides important empirical data for understanding and addressing the potential issues that electric vehicle onboard chargers may cause to the distribution system, and contributes to strategic recommendations for the proliferation of electric vehicles and the construction of future smart grids.