This study develops an SOH prediction model for electric vehicle batteries using periodic technical inspection data collected under driving conditions. As the EV market expands rapidly, accurate SOH estimation is essential for battery safety management, maintenance optimization, and circular economy policy design. The model employs Ridge regression with L2 regularization to address multicollinearity among key predictors as vehicle age, cumulative mileage, total operating time, and total discharge. Cross-validation results showed MAE=2.24%p and RMSE=2.74%p, outperforming a random forest baseline. Variable importance analysis revealed that age and mileage were the strongest predictors, with calendar aging and cycle aging contributing comparably to SOH degradation. A framework is proposed to estimate time-to-threshold for SOH criteria using daily usage patterns. This supports targeted inspection scheduling, residual value assessment for used EVs, and policy development for battery reuse and recycling. By leveraging large-scale field inspection data, the research bridges the gap between laboratory-based SOH modeling and practical diagnostic applications for EV safety management.