Recently, changes in the electric vehicle transition policy have necessitated improved user acceptance by securing the competitiveness of electric vehicles over internal combustion engine vehicles. In particular, the importance of reliable condition diagnosis technology to prevent safety accidents such as battery pack fires has been receiving significant attention. However, lithium-ion battery packs, primarily used in domestic electric vehicles, require the development of battery pack health diagnosis technology that considers real-world driving characteristics, such as high energy density and irregular and incomplete charge/discharge patterns. This study utilized OBD-II data from 100 real-world electric vehicles to extract health indicators for assessing battery pack aging over time using IC curves. Using IC curves during charging, the most stable environment during real-world driving, key factors associated with battery pack aging were identified. The IC curves confirmed that aging increased with mileage from 30,000 km to 260,000 km, demonstrating the potential for developing integrated aging maps for the same vehicle model. Furthermore, this study is considered a practical tool for immediate condition assessment of electric vehicles without the need for additional equipment.