Remaining Useful Life Prediction of Lithium-Ion Batteries Using Lag-Llama Model with Auto-Correlation Analysis

Predicting accurate capacity degradation and re-maining useful life (RUL) of lithium-lon battery is critical to health management and safe operation. However, variations in operating conditions and the variety of battery types present challenges to data-driven predictive models. Most data-driven methods rely on traditional machine learning models, which often have constrained predictive and generalization abilities. In this paper, a foundation model: Lag-Llama is used to predict capacity and RUL of battery with auto-correlation analysis. Firstly, the tokenization scheme of Lag-Llama is improved by auto-correlation analysis, which calculate the most probable periods in history capacity sequence. It is helpful for model to comprehend the capacity fluctuation pattern. Then, Lag-Llama is pre-trained to learn battery capacity degradation, and thus calculate the RUL. Additionally, the model is fine-tuned with a small amount of data to update the top-level module for application to the target cell. Finally, experimental results show that the proposed model exhibits accurate RUL prediction and strong transfer capability, within the average mean square error and absolute error less than 0.035 and 9 respectively.