Health monitoring and remaining useful life estimation of lithium-ion aeronautical batteries

Batteries are essential components of any aircraft electrical system. They are used to start the aircraft propulsion engines and to provide power during electrical emergencies. As is the case with most aircraft components, batteries exhibit aging and health degradation during operation. Therefore, the correctly estimation of the battery state-of-health (SoH) and of the remaining useful life (RUL) is important to aircraft operators. Failure to do so can result in underutilization of the equipment (if it is removed before the end of its life cycle) or unpredicted failure events during operation (when the battery SoH is overestimated). The consequences can range from increased operation costs to reduced flight safety. This article first presents the life cycle of lithium-ion aeronautical batteries. Then a method is proposed to generate discharge, capacity and health monitoring models during the battery life cycle. It is shown how these models are used to estimate the battery SoH and RUL. The method is validated using data from the NASA Ames Prognostics Data Repository. The models are implemented using MATLAB/Simulink and used to simulate a typical battery in different operational conditions.