As electric vehicles play a significant role in the climate crisis, battery technologies undergo a rapid development. For a reliable and safe application of LIBs, a precise state estimation is necessary. Currently, the State of X (SOX) of LIBs are determined based on voltage, current and temperature. The application of multiple sensor types enables more precise estimations, for not only first-life applications but also second-life integration of LIBs. In this study, strain gages have been applied to cylindrical cells to disclose the correlation between strain and SOC.