What is the required contact resistance for the power terminals of a charging connector, and what are the effects of excessive contact resistance?
According to IEC 62196 and GB/T 20234 standards, the contact resistance of power terminals in charging connectors under rated current is generally required not to exceed 0.5mΩ (milliohm), while signal terminals (CP/PP) typically require no more than 5mΩ. Specific limits should follow the product specification and applicable standard clauses.
Hazards of excessive contact resistance:
1. Abnormal heating: Per Joule's law P=I²R, a slight increase in contact resistance under high current causes significant heat generation — for example, 0.5mΩ at 250A generates 31W of heat;
2. Accelerated aging: Sustained high temperature accelerates terminal oxidation and insulation degradation, creating a vicious cycle of "temperature rise → oxidation → resistance increase → more heat";
3. Reduced charging efficiency: Increased contact voltage drop causes energy loss and lowers charging efficiency;
4. Safety risk: In extreme cases, it may lead to terminal welding, insulation breakdown, or even fire.
DEGSON charging connectors use high-conductivity copper alloy terminals with precision plating technology, and every unit undergoes contact resistance inspection before shipment, ensuring compliance with standard limits even after long-term operation.
Hazards of excessive contact resistance:
1. Abnormal heating: Per Joule's law P=I²R, a slight increase in contact resistance under high current causes significant heat generation — for example, 0.5mΩ at 250A generates 31W of heat;
2. Accelerated aging: Sustained high temperature accelerates terminal oxidation and insulation degradation, creating a vicious cycle of "temperature rise → oxidation → resistance increase → more heat";
3. Reduced charging efficiency: Increased contact voltage drop causes energy loss and lowers charging efficiency;
4. Safety risk: In extreme cases, it may lead to terminal welding, insulation breakdown, or even fire.
DEGSON charging connectors use high-conductivity copper alloy terminals with precision plating technology, and every unit undergoes contact resistance inspection before shipment, ensuring compliance with standard limits even after long-term operation.