The mechanical response of battery cells plays an important role in electric vehicle design, particularly in crashworthiness assessment and in evaluating how cell swelling affects overall battery performance. To accurately represent batteries in computational models, their response must be studied across multiple length scales. In this presentation, we introduce a multiscale modelling and calibration framework for predicting the mechanical response of the cell components, the stack and the jellyroll, see [1]. The proposed framework considers three length scales: (i) resolved electrode material (microscale), (ii) the level of the cell stack (mesoscale) and (iii) the jellyroll (macroscale). It utilises experimental input data (from different length scales) and enables calibration of material parameters. Effective models are introduced at each level, and the relation to underlying length scales is defined using computational homogenisation. Previous work is extended by incorporating an anisotropic volumetric hardening material model, cf. [2], for the jellyroll at the macroscale. In this study, experimental data from the literature at the electrode level (microscale) and the stack level (mesoscale) are employed. Two design optimization loops are established to demonstrate how the framework can be used to identify material parameters at the microscale (downscaling) and macroscale (upscaling). The simulation results show close agreement with experimental observations for both jellyroll specimens and a complete prismatic battery cell subjected to mechanical intrusion loading. By separating the length scales and employing homogenization and calibration schemes, the mechanical response of individual material layers can be estimated at their respective scales, enabling improved insight into battery cell behaviour under mechanical loading [1]. REFERENCES [1] D. Carlstedt, A. Chetry, C. Larsson, A. Purantagi, P. Gustavsson, F. Larsson and L.E. Asp. Multiscale Modeling and Calibration Framework for Predicting the Mechanical Response of Li-ion Battery Cell Components. Journal of Power Sources, Vol. 659, 238237, 2025. [2] P. Li, Y. B. Guo, and V. P. W. Shim. A constitutive model for transversely isotropic material with anisotropic hardening. International Journal of Solids and Structures, vol. 138, pp. 40–49, May 2018.