Electric vehicle charging receptacles are the main interface between the power grid and charging the electric vehicles high voltage battery. Due to architecture constraints and production costs, electrical contactor failure modes due to overheating at the receptacle are commonly inferred from temperature sensors and may not be discovered until damage of the receptacle unit has occurred. This paper reviews the current state-of-art for electric propulsion design principles and electric vehicle charging receptacles in North America. Existing mathematical models that can potentially be implemented to represent an electrical contact terminal and thermal power losses for an electric vehicle’s receptacle are reviewed. A thermo-electric nonlinear state-space model was selected for development and model-based estimation strategies including the Kalman Filter, Extended Kalman Filter, Unscented Kalman Filter and Sliding Innovation Filter strategy are then applied for evaluation. With the use of MATLAB software, a real-time simulation is developed to represent the receptacle, tune parameters in the filtering strategies and inject various fault scenarios related to thermal overheating. The model developed provides an efficient, low complexity solution to a problem that has relied heavily on high cost sensors and rigorous materials analysis. The three latter filtering strategies provide robust solutions for real time tracking of Joule heating in high voltage electrical connectors without the need for additional sensors.