How Do Liquid Cooling Rapid Chargers Work?

Liquid cooling rapid chargers use liquid-cooled cables to help combat the high levels of heat associated with high charging speeds. The cooling takes place in the connector itself, sending coolant flowing through the cable and into the contact between the car and the connector. Because the cooling takes place inside the connector, the heat dissipates almost instantly as the coolant travels back and forth between the cooling unit and the connector. Water-based liquid cooling systems can dissipate heat up to 10 times more efficiently, and other liquids can further improve cooling efficiency. Therefore, liquid cooling is receiving more and more attention as the most efficient solution available.

 

Liquid cooling allows the charging cables to be thinner and lighter, reducing the cable weight by around 40%. This makes them easier for the average consumer to use when charging their vehicle.

 

Liquid cooling fluid connectors are designed to be durable and withstand external conditions such as high levels of heat, cold, moisture and dust. They’re also designed to withstand massive amounts of pressure to avoid leaks and sustain themselves throughout long charging times.

 

The liquid cooling process for electric vehicle chargers typically involves a closed-loop system. The charger is equipped with a heat exchanger that is connected to a cooling system, which can be either air-cooled or liquid-cooled. The heat generated during charging is transferred to the heat exchanger, which then transfers it to the coolant. The coolant is typically a mixture of water and a coolant additive, such as glycol or ethylene glycol. The coolant circulates through the charger’s cooling system, absorbing heat and transferring it to a radiator or heat exchanger. The heat is then dissipated into the air or transferred to a liquid cooling system, depending on the design of the charger.

With liquid cooling for the contacts and the high-performing coolant , the power rating can be boosted up to 500 kW (500 A at 1000V) that can deliver a 60-mile range charge in as little as three to five minutes. 

The interior of a high-power CSS connector shows the AC cables (green) and liquid cooling for the DC cables (red). 

 

Charging Cable Parameter

Parameter Specification
Rated Voltage 1000V Max
Cable Bending Radius ≤300mm
Rated Current 500A Max(Constant Current)
Cable Length 5 meters Max
Maximum Power 500KW Max
Cable Weight 1.5kg/m
Withstand Voltage 3500V AC/1 minute
Working Altitude ≤2000m
Insulation Resistance(at Normal Temperature) ≥2000MQ
Plastic Material Thermoplastic
Compliance with IEC 62196-1 under Hot and Humid Conditions Chapter 21 Requirements
Terminal Material T2 Copper/Brass
Terminal Surface Treatment Silver Plating
Temperature Sensor Type PT1000
Liquid Cooling System Size 415mm*494mm*200mm(W*H*L)
Temperature Sensor Intervention Value 90
Liquid Cooling System Operating Voltage 24V DC
Gun Head Protection Level IP55
Liquid Cooling System Operating Current 12A
Liquid Cooling System Protection Level Pump, Fan:IP54 /No Protection
Liquid Cooling System Power 288W
Insertion and Extraction Force ≤100N
Plug and Unplug Life 10,000 times(No Load)
Liquid Cooling System Weight 20kg
Operating Ambient Temperature -30~50
Coolant Insulating Silicone Oil
Flame Retardant Grade UL 94-V0
Coolant Flash Point >200
Conductor Specification 35mm²(Liquid Cooling)
Coolant Dielectric Strength 15KV
Conductor Heat Loss 1300KW(5 Meters of Wire, 500A Current)
Working Flow Value 3-6LPM(25 Environment)
Cable Color Black
Working Pressure of Liquid Cooling System 0.7MPa Max
Cable Outer Diameter Ø33.5±1mm
Maximum Allowable Pressure 0.8MPa Max
Cable Jacket Material TPU
Coolant Maximum Temperature 80