Comparative Evaluation of 600 V and 800 V Battery Architectures for Urban Electric Buses: Energy Efficiency and Range Analysis

In this study, the impact of different battery voltage architectures on energy efficiency, driving range, and charging performance of urban electric buses was analyzed using a MATLAB/Simulink-based simulation model. The objective was to comparatively evaluate the effects of 600 V and 800 V battery systems on overall vehicle energy management. The model consisted of vehicle dynamics, electric motor, battery system, and charging subsystems. Three scenarios were investigated: (S1) a 600 V system with 350 kWh capacity, (S2) an 800 V system with 490 kWh capacity, and (S3) an 800 V system with 352 kWh capacity. All scenarios were simulated under the SORT-1 driving cycle between 100% and 20% state of charge. Results showed that the 800 V architecture achieved approximately 1.1% lower normalized energy consumption (Wh/ton·km) compared to the 600 V system with similar capacity. Increasing battery capacity from 350 kWh to 490 kWh extended the driving range by about 39%. Charging analysis indicated comparable charging durations for equal energy transfer, while the 800 V system enabled lower current levels, reduced transmission losses, and improved fast-charging efficiency. The findings demonstrate that battery voltage level and pack configuration play a critical role in the energy efficiency and operational performance of urban electric buses.