Electric Vehicles (EVs) and plug-in hybrid vehicles are revolutionizing transportation at various levels. The demand for EVs in different sectors is at an all-time high and trending upward.
The Importance of EV Charging Infrastructure
The emerging EV charging station networks play a key role in facilitating the growth of EV adoption. Thanks to standardization and technological advancements, EV charging is now much more accessible at many locations, including homes, workplaces, commercial buildings, and on the roads.
Understanding EV Charging Technologies
To have the best EV experience, it is essential for current and future EV owners to educate themselves about the available EV charging technologies. There are three types of EV chargers:
- Level 1: These are slow AC chargers powered from standard 120V outlets.
- Level 2: These are fast AC chargers powered from specialized 240V sources.
- Level 3 or “DC Fast” Chargers: These are high-power DC fast chargers that offer the highest charging rate.
In this article, we introduce the basics of EV charging technology, different types of EV chargers, and provide guidance on choosing the right charger for your needs.
Discover more about the best EV charging options for your vehicle today!
Basics of EV Charging Technology
Electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) rely on battery packs that require DC power, while the utility grid supplies AC power. To charge an EV, an essential component called the EV charger bridges the gap between the AC source (utility grid) and the DC load (battery pack), efficiently converting power.
Most EVs and PHEVs on the market today include an on-board charger (OBC) that allows owners to charge their vehicles using standard 120V/240V AC outlets through Electric Vehicle Supply Equipment (EVSE), also known as AC chargers. EVSEs ensure a safe charging process and can manage energy consumption according to Time-of-Use (TOU) tariffs set by utility providers. EVSEs are categorized into Level 1 and Level 2 chargers based on their power output.
Due to size and weight constraints of the OBC, charging speed can be limited. To address this, DC fast charging technology has evolved, enabling rapid charging. This method employs off-board high-power DC fast chargers (commonly referred to as Level 3 chargers), which use specialized three-phase AC sources to supply DC power directly to the vehicle’s battery pack, bypassing the OBC. Level 3 charging is the fastest option available, ideal for commercial settings where high-power demand is prevalent.
Emerging technologies such as wireless charging methods are also being explored for EVs, allowing energy transfer from the charger to the vehicle without physical connections. While this innovative solution shows promise, it is still in the early stages and not yet widely available to the public.
The image below summarizes the basic EV charging methods and the components involved in each solution.
Different Types of EV Chargers
There are three main types of charger that are defined based on the nature of power and the power ratings which translates to charging speed. These three main types are Level 1, Level 2, and Level 3 chargers.
What are Level 1 Chargers?
Understanding Level 1 chargers starts with knowing that they are connected to standard 120V wall outlets, providing AC power to the vehicle’s on-board charger, which converts it to DC power for the battery. These chargers are the slowest option, with a maximum power output of 1.4 kW, typically adding around 5 miles of range per hour.
Key Features of Level 1 Chargers:
- Maximum Power Output: 1.4 kW
- Charging Speed: Adds approximately 5 miles of range per hour
- Installation: Simply plugged in; no installation needed
Level 1 chargers usually come with electric vehicles (EVs) and can also charge plug-in hybrid electric vehicles (PHEVs). Given their slow charging rate, Level 1 chargers are best suited for overnight charging and daily top-offs.
How about Level 2 Chargers?
Level 2 chargers supply a maximum of 240V AC power to an electric vehicle’s on-board charger unit. With a maximum power output of around 19.2 kW, Level 2 chargers can add approximately 80 miles of range per hour, making them an efficient choice for EV owners. These chargers are usually sold separately, either by the car manufacturer or through third-party suppliers.
Key Features of Level 2 Chargers:
- Power Output: Up to 19.2 kW
- Charging Speed: Adds about 80 miles of range per hour
- Types: Available as hardwired or plugged-in (a NEMA 14-50 receptacle needed)
In either case, the assistance of a licensed electrician is needed to install the charger and ensure that the breaker sizing is correct. Level 2 chargers provide a much faster charging experience than Level 1 chargers and can fully charge an EV overnight. Level 2 chargers are best for home installations and often found in public areas such as workplaces, schools, shopping centers, etc.
What are Level 3 Chargers?
Level 3, or DC Fast chargers, are the fastest viable charging option for EV owners. These chargers are supplied from high-power three-phase AC sources and provide high-power DC to the electric vehicle. Level 3 chargers with power outputs of 120kW, 180kW, and 360kW are often found in commercial charging stations and can add several hundred miles of range per hour.
Key Features of Level 3 Chargers:
- Power Output: Several hundred kW of output power
- Charging Speed: Several hundred miles of range per hour
- Types: Available in a commercial settings such as charging stations
There are a variety of technical considerations when choosing the right DC fast charger for your application. The installation of these heavy-duty units requires detailed expertise, technical knowledge, accurate planning, and should be handled by professional project management. Recent technological advancements allow for MegaWatt Charging Systems (MCS) to become commercially available and used for heavy-duty fleet applications.
Common Types of Charging Connectors in North America
The standardized connectors for electric vehicles (EVs) vary across models and regions. In North America, however, there are three main types of connectors widely adopted by electric vehicle and plug-in hybrid electric vehicle (PHEV) manufacturers:
- SAE J1772: Used for AC charging
- CCS1: Used for DC fast charging
- NACS: Compatible with both AC and DC charging
All EVs sold in North America, other than Tesla, are compatible with SAE J1772 for Level 2 and CCS1 for Level 3 charging, respectively. In contrast, Tesla EVs are exclusively compatible with NACS connectors for both AC and DC charging. Fortunately, adapters (CCS1-to-NACS and J1772-to-NACS) are available from third-party suppliers, enabling EV drivers to use any charging station to recharge their vehicles.
Installation of Level 2 EV Charger at Home
Most of the EVs sold in North America come with a Level 1 charger that can be plugged into any standard 120V outlet. However, if you need a faster charging rate at home, consider installing a Level 2 charger. Popular options include brands such as Autel, ChargePoint, and Tesla Wall Connector.
Ensuring Compatibility with EVs
All Level 2 chargers on the market are built to work with any electric vehicle (EV) and have a J1772 type connector. Tesla’s Wall Connector comes with a NACS type connector and is primarily designed for charging Tesla vehicles. However, by using the appropriate adapter (NACS-to-J1772), this charger can also charge other EVs.
Ensuring Professional Installation of EV Chargers
A home EV charger should be installed by licensed electricians to ensure safety and code compliance. Technical considerations for installation include:
- Capacity of the electrical panel
- Correct breaker and wire sizing
- Installation location and distance from the electrical panel
- Conduit setup and wire pulling
- Physical installation requirements
Home EV Chargers, In a Nutshell
Available Level 2 home chargers are compatible with most electric vehicles sold in the US market. Tesla Wall Connectors require an adapter to charge other EVs. If you decide to enhance your EV experience by installing a home charger, it is recommended to consult and hire a licensed electrician for a safe and compliant installation.
Ready to enhance your EV charging experience? Consult a licensed electrician today!
