Kwun Tong District EV Charger Locations

1) Inside EV Link a mother board with a 24V power supply commanding a contact is installed. 
2) Less than 100W of consumption when the CT is closed. We are just a gate between the grid and the car.

So the maximum consumption is 100w (dedicated to 24v power supply, motherboard, contactor and led). Efficiency will be, 
If the load is a 3,7kW (16A 1P) efficiency = 97%
If the load is a 22kW (32A 3P) efficiency = 99,5%  

But, also consider the Harmonics, Power factor produced by the Car itself which will affect efficiency.

AC chargers (Level 1 & 2) provide power in alternating current, which gets converted to direct current by the car's onboard charger.
DC chargers (Level 3) provide power directly in direct current, allowing for faster charging times.

Connection: DC fast chargers use specific connectors like CHAdeMO (used by Nissan), CCS (supported by many European and American carmakers), and Tesla Superchargers (exclusive to Tesla).

Direct Power: Unlike regular chargers that supply alternating current (AC) and depend on the vehicle's onboard charger for conversion to direct current (DC), fast chargers deliver DC power directly to the vehicle's battery, enabling quicker charging.  

Communication: Upon connection, the vehicle and charger communicate. The charger understands the battery’s state, capacity, and power acceptance level, ensuring safe and efficient charging.  

Charging Phases:
Constant Current: Initially, the charger supplies a consistent high current for rapid charging.  

Constant Voltage: As the battery nears full capacity, the charger maintains voltage while decreasing current to prevent overcharging.    

Cooling: Due to the heat generated during fast charging, cooling mechanisms are employed in both chargers and vehicles. Some chargers use liquid-cooled cables, while vehicles activate cooling to maintain battery temperature.  

Safety: Charging starts only after a secure connection is confirmed. Built-in systems prevent overcharging and ensure power is transferred safely.  

Infrastructure: These chargers require a strong electrical setup, often with dedicated transformers, to manage high power demands.  

User Interface: Public stations often have interfaces for payment, charging progress tracking, and other features.  

In summary, fast EV chargers provide direct current for rapid charging, communicate with vehicles for optimal charging, have cooling and safety systems, and need robust infrastructure support. They're ideal for long-distance travel or when time is limited.