How it works
Most Electric Vehicles nowadays charge using the mode 3 charging protocol.
This means the car and charger talk to one another to agree on how and when to charge.
The connectors used in mode 3 charging have 7 pins in total:
- 1 earth pin
- 1 neutral pin
- 3 phase pins
- 2 small signal pins (called pp and cp)
The neutral and phase pins provide the electricity for charging of course, while the 2 small pins control how the car will be charged (they actually provide the mode 3 charging signals)
As soon as you plug a connector into the charger or the car, the device knows the maximum current the charging cable is designed for. How does it know? Because a small resistance is built into the connector between the earth and pp pins. Depending on the resistance the car and the charging device know they have to limit the max current to prevent overheating the charging cable.
So, if you have a 16A rated cable, you will never be able to charge faster then 16A per phase. If you have a 32A rated cable, you will be able to charge at any rate below or equal to 32A
The other signal wire (Control Pilot wire) provides the communication between car and charging station. Using a wave generation and a combination of resistors, the vehicle tells the charger what the maximum charging current is (allthough it can never surpass the cable capacity as described above), and whether to start charging.
This enables the vehicle to start charging at a certain pre-programmed time, and at a specific rate dictated by the car.
In Europe, 2 types of connectors are used for mode 3 charging, namely the Type 2 connector (often referred to as the Mennekes connector) and in France and Italy also the Type 3c connector proposed by Schneider Electric (F) and Scame (IT). The reason being that for those 2 countries, federal regulation stipulates that every public electric connection should be shielded from direct human contact.
|The EV-Alliance Type 3C EV Connector||The Mennekes Type 2 EV Connector|
As you can see from the images above, the Type 3C connector has a cover and a shield that will only open when you push the connector in the charge box. The Type 2 connector has no such shielding, allthough Mennekes has recently released a wall socket with a diafragm. Those in favor of Type 2 connectors state that there can never be any danger for electrocution, because the charger and car never allow electric current on the pins unless both connectors have been inserted into their sockets...
The battle between Type 2 and Type 3 is still going on in Europe, but clearly shifting in favor of type 2, resulting in Electric Vehicle owners being presented with 2 different charging options, depending on the country they travel to.
In France and to a lesser degree Italy, some public charging infrastructure still uses Type 3C charging infrastructure, which means that sometimes vehicles need a charging cable with a male Type 3C connector and a female Type 2 connector for the vehicle side.
These cables are far from common, in contrast to the widely used Type 2 to Type 2 cables. That is why evChargeKing started production of these cables to help out all European travellers going to France or Italy.