How many amps does a home EV charger use?

With an increasing number of people turning to electric vehicles (EVs), the types of EV chargers and the amount of current they use in amperes are becoming a topic of greater interest. The following is a brief introduction to these subjects.

1. What is an ampere?

An ampere, or amp for short, is the basic unit of electric current in the International System of Units, symbolized by “A.” For EV chargers, the ampere rating indicates the amount of current that can be supplied to the battery system over a given period of time.

2. How many amperes do EV chargers use?

EV chargers can generally be divided into two categories: home EV chargers and public EV charging stations.

2.1 Home EV chargers:

These are typically classified into Level 1 and Level 2 EV chargers.

Level 1 chargers: These are the most basic type of charger and usually operate on a standard 120-volt outlet. They typically provide a current of 12 to 16 amps. In one hour of charging, they can add about 3 to 5 miles of range. The advantage is that they are often included with the vehicle, making them convenient to use and allowing you to charge almost anywhere. The downside is their slow charging speed. However, given that electricity rates are lower during off-peak hours at night, they are commonly used for overnight charging.

Level 2 chargers: These chargers use a 240-volt outlet and typically provide a current of 16 to 40 amps. In one hour of charging, they can add about 20 to 60 miles of range. The main advantage is their faster charging speed, which can easily meet the basic needs of daily travel. The downside is that they are more expensive, more complex to install, and take up more space.

2.2 Public EV charging station:

To meet the charging speed and vehicle requirements of most EVs, public charging stations offer a variety of current outputs. These are usually Level 2 and Level 3 charging stations.

Level 2 charging stations: These use a 240-volt AC power supply and typically provide a current of 16 to 40 amps. In one hour of charging, they can add 20 to 60 miles of range, depending on the vehicle and charger power. Since these are public charging stations, they commonly use the Type 2 connector, which is widely adopted by most EVs. Some stations also have adapters to accommodate other types of charging connectors.

Level 3 charging stations: These use a high-voltage DC power supply, ranging from 400 to 800 volts, and typically provide a current of 100 to 350 amps. They can add over 100 miles of range in a short period of time, depending on the vehicle and charger power. Common connectors include CCS and CHAdeMO, and some stations have adapters to fit other types of connectors.

3. Factors to consider when choosing a charger with different amp ratings

3.1 Home electrical capacity

It is essential to ensure that your home electrical system can support the rated current of the charger. Generally, the maximum load capacity of a home circuit should be at least 80% greater than the charger’s rated current to ensure that the electrical system can handle the additional load from the EV charger.

3.2 Vehicle compatibility

It is best to choose a charger that matches the maximum input current of your vehicle. However, if the charger’s current is higher than the vehicle’s maximum input current, charging can still occur, though it may result in some wasted electricity.

3.3 Daily travel needs

If you have an urgent trip, a faster Level 2 charger is a better choice. If not, a Level 1 charger is recommended. Generally speaking, fast charging can have some negative impacts on the battery.