Latent thermal energy storage (LTES) systems have great potential but the number of real-life applications are limited. Although the necessity for high-quality experiments can not be argued with, the resulting conclusions from a large amount of research testing specific heat exchangers are all too often not very useful. In spite of the experimental work, the complex transient nature of LTES systems, the high cost of experimental set-ups, and the accompanying measurement uncertainty, makes it necessary to develop physics-based models to predict and evaluate the performance of a LTES heat exchanger. The recently developed charging time energy fraction method includes such a model. However, the method itself still has some shortcomings. Therefore, in this work, this method is further developed. A methodology is proposed which splits a full charging cycle into two relevant subprocesses by splitting the stored energy into relevant parts corresponding with the respective two subprocesses. Charging time correlations for each of the two subprocesses are calibrated on simulation results. Then a methodology is proposed for combining the two charging time correlations and essentially predicting the HTF outlet temperature for a full charging cycle. Accurate predictions are obtained and a full characterization is possible of a LTES heat exchanger through the charging time energy fraction method.