When sourcing auto contactors, you must prioritize Rated Operational Voltage (Ue) and Rated Operational Current (Ie) to ensure they match your system's power requirements. For automotive applications, specifically EVs, look for High-Voltage DC Contactors capable of handling 400V to 800V DC. Additionally, verify the Utilization Category (e.g., AC-3 for squirrel-cage motors or DC-1 for non-inductive loads) and ensure the Coil Voltage (e.g., 12V, 24V, or 220V) is compatible with your control circuit. Contact material (such as silver alloy) is critical for minimizing electrical wear and extending the mechanical life cycle (typically >1 million operations).