Electric current is used in an array of different fields, be it in the home, businesses, industry or for charging electric vehicles. However, there are two types of electric current: single-phase current and three-phase current. What is the difference between them and how can you know whether your EV is single-phase or three-phase?
The difference between single-phase and three-phase current
Single-phase current is the norm in most households. It features an alternating current which peaks and dips in a cycle between a positive and a negative value.
Three-phase current can also be found in households. However, it is mainly used in industry, factories, large companies and high-performance facilities. Unlike single-phase current, three-phase current uses three separate voltage supplies.
Knowing whether a vehicle is single-phase or three-phase by its connector type
The EV connector, also called a charging port, determines whether the vehicle charges in single-phase or three-phase. EVs are equipped with a dedicated connector which can be used to plug into single-phase or three-phase charging stations. If the vehicle’s connector is not identical to the charging station, the charging capacity will be automatically limited.
- Single-phase EV → at a three-phase charging station: charging capacity limited by the vehicle
- Three-phase EV → at a single-phase charging station: charging capacity limited by the charging station
To check whether a vehicle is single-phase or three-phase, all you need to do is open your EV’s charging port flap and count the number of power contacts contained in the charging port.
The connector of a single-phase electric vehicle is made up of 3 power contacts.
To charge a single-phase EV, you can choose a single-phase charging cable. Single-phase charging cables have a maximum charging capacity of 7kW. They allow you to charge a single-phase EV at single-phase charging stations (7kW) in optimum conditions.
The connector of a three-phase vehicle is made up of 5 power contacts.
Three-phase electric vehicles will require a three-phase charging cable to be able to charge in optimum conditions. Charging three-phase EVs via a three-phase cable from a 22kW charging point (three-phase) provides you with rapid charging in the best conditions.
Some vehicles are equipped with a two-phase connector. Two-phase connectors are made up of 4 power contacts. This configuration is not so common, but can be found on some recent models such as the Volkswagen E-up and some models marketed by Skoda, Seat and Mercedes.
For these vehicles, three-phase charging solutions are the most suitable.
Some specific cases
There are a few specific cases where it is not necessarily a good idea to buy a cable that matches your vehicle:
- If you are thinking of swapping your single-phase EV for a more recent version, it is more financially sound to purchase a three-phase charging solution which you will be able to use in the future. New electric vehicles tend to be equipped with a three-phase connector for faster charging.
- For some home installations, it may be more advantageous to buy a charging station that doesn’t have the same power rating as your EV. For advice on this topic, contact your electrician or a qualified charging station installer.
- For three-phase EVs with an 11kW on-board charger, you can consult our special purchasing guide for 11kW EVs.
In short, the main difference between single-phase and three-phase current is the number of voltage supplies used. Single-phase current uses a single alternating voltage supply, whereas three-phase current uses three alternating voltage supplies providing three phase cycles that offset each other. It is essential to know whether your EV is single-phase or three-phase in order to opt for the right charging solution and enjoy an optimum charging experience. Charging cables and stations are available in a range of charging capacities to meet the requirements of all EVs on the market and various electrical installations.
To make it easier for you to purchase a charging cable or station, a power rating equal to or less than 7.4kW points you in the direction of a single-phase charging solution and higher power ratings, such as 11kW and 22kW refer to three-phase charging solutions.