Predicting BESS Degradation with Uncertainty Quantification: A Probabilistic Framework for Battery Energy Storage Systems

Melina Graner, Holger Hesse, Andreas Jossen

Accurate and uncertainty-aware prediction of battery degradation is essential for the reliable operation and lifecycle management of energy storage systems, yet traditional deterministic models fail to capture the inherent uncertainty in degradation processes. This study introduces a framework for probabilistic battery state-of-health prediction. The framework leverages deep learning models to generate predictive distributions for capacity loss, conditioned on stress factors. Uncertainty is propagated through stochastic degradation trajectories, enabling robust predictions even under dynamic operating conditions. A key advancement is the framework's scalability to full-system data: by integrating cell-level predictions with system topology and real-world operational variability, it provides probabilistic estimates for entire battery energy storage systems. The approach is tested using multi-year field data from residential storage systems, demonstrating its ability to mimic system-level degradation behavior. The framework predicts SOH degradation with 95\% prediction intervals that align well with remaining capacity measurements performed on the field system. This work bridges the gap between laboratory test derived battery cell aging models and full-system operational data evaluation for degradation estimation, offering a practical tool for data-driven asset management in modern energy systems.