AC EV Chargers
AC EV Charger: Understanding the Basics and Benefits
AC (alternating current) charging is the most common method for charging electric vehicles (EVs), especially for those charging at home. It involves the conversion of alternating current (AC) from the power grid into direct current (DC), which is then stored in the EV's battery. This method is slower than DC (direct current) charging, but it’s highly practical for daily use, offering a reliable and convenient way to charge electric vehicles when time permits.
In this article, we’ll explore the details of AC charging, including when it’s best to use, how it works, and its advantages. We’ll also look at the different types of AC chargers available and how they fit into the electric vehicle ecosystem.
When Should You Use AC Charging?
AC charging is ideal for situations where you have several hours to charge your vehicle, and you don’t need to worry about a rapid recharge. While DC fast chargers can refill your EV much faster, AC chargers are often more convenient and cost-effective for daily use. Here are some situations where AC charging is particularly well-suited:
1. Running Errands
If you’re parking your car for an extended period—whether for errands, shopping, or meetings—AC charging is a great option. While you’re away, the EV can charge without interrupting your plans. Depending on the charger’s capacity and your vehicle’s battery size, you can achieve a significant charge during a few hours of parking.
2. Working from Home
If you work from home and don’t need to drive your car throughout the day, an AC charger can be a convenient option for charging your EV continuously. While you’re working, your EV can be charging in the background, ensuring you have a full battery by the end of your workday.
3. Charging Overnight
Charging your EV overnight is one of the most common and efficient uses of AC charging. If you’re not using your car during the night, AC chargers can replenish your EV’s battery at a slow and steady rate. By the morning, you’ll have a fully charged vehicle, ready to take on the day without the need for a time-consuming charge during the day.
How Does AC Charging Work?
AC charging works through a process that begins with the power supply from the electric grid. This power travels to your EV’s onboard charger (OBC), which converts the AC electricity into DC electricity. This DC power is what actually charges the EV’s battery, which then stores the energy for later use.
The charging speed for AC chargers is measured in kilowatts (kW). The speed varies depending on the specifications of the charger and the vehicle. Most residential AC chargers deliver power between 3 kW and 7 kW, while more advanced chargers may provide up to 22 kW of power. It’s important to note that the vehicle’s onboard charger plays a significant role in determining how fast the vehicle charges, as it must be able to handle the incoming power from the charging unit.
AC chargers are often found in residential settings, but they are also commonly located at public charging stations, workplace charging points, and other locations where EVs are parked for extended periods. Charging overnight or when electricity rates are lower can help reduce the cost of charging your EV.
How Fast Are Level 2 AC Chargers?
Level 2 AC chargers are one of the most common types of home EV chargers. These chargers offer a moderate charging speed, typically ranging from 3 kW to 22 kW, depending on the charger’s specifications and the vehicle’s capacity for accepting power. A Level 2 charger generally provides about 25 to 30 miles of range per hour of charging, which is sufficient for most daily commuting needs.
For example, a Tesla Model 3 can charge from 0% to 100% in approximately 8 to 12 hours using a Level 2 AC charger. However, the exact time depends on factors such as the size of the battery, the charger’s power rating, and the state of charge when charging begins. Compared to DC fast chargers, Level 2 AC chargers are slower, but they provide a steady and reliable flow of power that is perfectly suited for overnight or long-term charging.
Where is AC Charging Commonly Used?
AC charging is most commonly used in residential settings, where it’s convenient to plug in the EV overnight. Since homes typically receive alternating current (AC) from the electrical grid, the system is designed to make use of this existing infrastructure.
The typical home charger is a Level 2 charger, which connects to a standard 240-volt outlet. For example, many homes in North America have a 240-volt outlet for large appliances, and this is where EV chargers can be installed.
AC chargers are also used in public charging stations and workplace charging facilities. While the charging speed is not as fast as DC chargers, they are still ideal for situations where vehicles will be parked for several hours, such as at a shopping mall or office building.
Which Vehicles Can Be Charged with AC Chargers?
AC chargers are compatible with a wide range of electric vehicles (EVs), including:
1. Battery Electric Vehicles (BEVs)
These vehicles run solely on electric power, with no internal combustion engine (ICE) involved. Popular examples include the Tesla Model 3 and Nissan Leaf. BEVs are fully reliant on electric charging, and AC chargers are ideal for charging these vehicles both at home and at public stations.
2. Plug-in Hybrid Electric Vehicles (PHEVs)
PHEVs are equipped with both electric and gasoline engines. They can operate in electric-only mode for a limited distance before switching to gasoline power. Examples of PHEVs include the Toyota Prius Prime and Ford Escape PHEV. While PHEVs can also be charged using AC chargers, they typically have smaller batteries, so charging times are shorter than those of BEVs.
3. Extended-Range Electric Vehicles (EREVs)
These vehicles have an electric motor that drives the wheels but also include a gasoline generator to extend their range when the battery runs low. The Chevrolet Volt is a notable example of an EREV. EREVs can be charged using AC chargers, and the combination of electric power with a gasoline backup offers greater flexibility for longer trips.
4. Hybrid Electric Vehicles (HEVs)
HEVs typically do not require external charging, as they rely on regenerative braking to recharge their battery. However, some HEVs may have a plug for limited electric-only driving, and can be charged using AC chargers. Popular examples include the Toyota Prius and Honda Insight.