China's GB/T DC is designed specifically for direct current charging, which is faster than alternating current (AC) charging, because direct current can be delivered directly to the battery. AC is used in homes instead of DC, so with AC charging, the car’s onboard charger must first convert AC power to DC.
For ultra-rapid charging, GB/T DC requires liquid-cooled cables to avoid damage caused by overheating. Inside those cables there are circulation channels containing a liquid coolant that absorbs and dissipates heat. The liquid cooling process involves a closed-loop system in which the coolant travels back and forth between the connector and the cooling unit of the charger.
The GB/T DC connector connectors can carry up to 800 A and 1500 V and it can deliver up to 1200 kW of power output. GB/T DC is the only DC fast charging protocol currently used in China.
The connector supports bidirectional charging, allowing EVs to send power back to the home, the grid, appliances or another vehicle, turning the car’s battery into a backup power source.