Electric vehicles (EV) are getting new standards gradually as their applications increase dramatically worldwide. The International Electrotechnical Commission (IEC) has standardized the charging modes for electric vehicles, defining four distinct modes. The standard is termed IEC 61851.
The IEC has previously standardized several other aspects of EV charging and operating. For instance, the IEC 61980 standard elaborates on the best practices for the EV Wireless Power Transfer (WPT) system.
EV Charging Modes
The four modes for EV charging are named Mode 1, Mode 2, Mode 2, and Mode 4. Mode 1 is for earlier EV converted internal combustion engine vehicles, so it’s not in use so much today with more advanced EVs.
EV Charging Mode 1
In mode 1, the vehicle connects directly with the standard available household socket. In these sockets, the maximum current is 16 A. The voltage can be no higher than 250 V on a single-phase system, and no more than 480 V if you have a three-phase system.
There’s no communication between the charging port and the car, so it’s not the most sophisticated charging connection. In fact, in many countries, this charging mode is prohibited, so you can’t really use it.
EV Charging Mode 2
To address the problems with household sockets (Mode 1), this mode uses a special type of cable that has a built-in control and safety device (IC-CPD). What this device does is control the flow of charge and prevent electric shocks.
The maximum current for charging on this mode is 32 A. Maximum voltage on a single-phase system is 250 V, and on a three-phase system, it’s 430 V. This mode deals with over-current and overheating problems, making charging EV safer.
Once the car is fully charged, the control device disconnects the power supply to the car, preventing any overcharging or overheating. This mode uses a Case B connection with the control box no more than 300 mm from the three-pin plug.
EV Charging Mode 3
Mode 3 of EV Charging uses a dedicated EVSE with an onboard charger. In fact, you can use any case of cable within this charging mode. The EVSE has all the safety features activated to ensure no issues occur during charging.
It ensures that the connection between the EVSE and EV is safe and that there’s a protective earth connection. The maximum current for Mode 3 is 250 A, with the same 250 V and 430 V limit for single-phase and three-phase systems, respectively.
This EVSE may be available publicly, but you also mount it to a wall in your home. This eliminates any live cabling other than when the car is charging.
EV Charging Mode 4
The EV Charging Mode 4 uses a case C connection as the cable is connected with the charging station permanently. It directly gives a DC output to the vehicle’s battery, eliminating the need for an onboard charger of EV.
Mode 4 can support 400 A maximum current with 600 V. This means that EVs may charge the fastest in this mode. However, due to more power, this mode follows even stricter safety and communication standards.
In reality, though, charging rates can vary by charging points. So while you may be using Mode 4 somewhere, it may not necessarily be quick.
Mode 3 and Mode 4 are the most common charging modes in countries with a large EV consumer base. These modes are safer as compared with Mode 1 and 2. Mode 4 is the only one that delivers DC current directly and bypasses the charger.
Standardizing these charging modes makes it easier for end consumers to ensure safety and understand their options better.