An approximate expression for single electrode heats have been derived and tested. Peltier coefficients of a metal electrode in contact with a molten salt mixture were first derived using irreversible thermodynamics of surfaces. The expression for the Peltier coefficient for the electrolyte side of the interface has the value of a one-component electrolyte as a basis and includes correction terms for multicomponent mixtures. Analyses of results reported in the literature for salt mixtures of AgX-BX and CuX-BX show how the correction terms vary when the electrode surface is chosen as the frame of reference for the transports. Here X represents a halide ion and B is an alkali metal. The expression is used to estimate electrode heats for the B/BX electrode within 10-20% accuracy. The error is mainly due to neglect of the transported heat in the electrolyte.