A method of monitoring the voltage transmitted through a pair of electrical connector devices is provided. The pair of electrical connector devices include a source connector coupled to a power supply and a load connector coupled to a load, the source connector being coupled to the load connector. The method includes determining the voltage utilized by the load, determining the voltage generated by the power supply, and determining an electrical resistance of the pair of electrical connectors using the determined voltage utilized by the load and the voltage generated by the power supply. A connector monitoring circuit and a portable X-ray detector including the connector monitoring circuit is also provided.