The introduction of fully electric vehicles (FEVs) into the mainstream has raised concerns about the reliability of their electronic components such as IGBT. The great variability in IGBT failure times caused by the very different operating conditions experienced and the stochasticity of their degradation processes suggests the adoption of condition-based maintenance approaches. Thus, the development of methods for assessing their healthy state and predicting their remaining useful life (RUL) is of key importance. In this paper, we investigate the results of performing accelerated aging tests. Our objective is to discuss the design and the results of accelerated aging tests performed on three different IGBT types within the electrical powertrain health monitoring for increased safety (HEMIS) of FEVs European Community project. During the tests, several electric signals were measured in different operating conditions. The results show that the case temperature (T-C), the collector current (I-C), and the collector-emitter voltage (V-CE) are the failure precursor parameters that can be used for the development of a prognostic and health monitoring (PHM) system for FEV IGBTs and other medium-power switching supplies.