What is Electric Vehicle Supply Equipment(EVSE): Types & Features

Electric Vehicle Supply Equipment (EVSE) refers to the infrastructure and components essential for charging electric vehicles (EVs). Often known as charging stations, charging docks, or simply chargers, EVSE provides power supplies to recharge electric vehicle batteries. This comprehensive system includes charging stations, connectors, cables, and control systems, all meticulously designed to deliver electricity safely and efficiently to EVs. EVSE is categorized into Level 1, Level 2, and Level 3 (DC fast charging), each offering different charging speeds and power levels.

EVSE can generally be understood as consisting of three main components: software, charging equipment housing, and plug. To better understand EVSE, let’s look at these essential elements that power EVSE.

Housing/Enclosure

EVSE housings are designed in various configurations to meet diverse charging needs. Standalone boxes are commonly employed for home charging setups, offering a compact and user-friendly solution. Wall or pedestal-mounted enclosures provide flexibility for multi-family residential, workplace, and other public charging environments, ensuring accessibility and convenience. Towers, prevalent at public charging stations or commercial fleet depot locations, consolidate multiple charging points into a single structure, optimizing space and resources. These enclosures are typically constructed using durable materials such as weather-resistant plastics or metals, safeguarding essential EVSE components from environmental elements. There are normally 3 types:

Standalone Boxes

A simple home charging solution where the charger is housed in a box attached directly to the charging cable.

Wall or Pedestal-mounted Enclosures

Versatile solutions for homes, workplaces, multi-family residences, fleets, hotels, retail spaces, and public charging areas. Wall-mounted units attach to buildings, while pedestal-mounted units stand independently for flexible placement.

Towers

Designed for public stations and fleet depots, these tall structures integrate multiple charging points into a single, space-efficient unit.

Firmware

The firmware embedded within EVSE components serves as the brains behind the charging operation, enabling advanced functionalities and ensuring compatibility with a wide range of electric vehicles. This microcode governs various aspects of charging management, including initiating and terminating charging sessions, implementing cybersecurity measures to protect against unauthorized access or tampering, and facilitating communication between the EVSE and the vehicle's onboard systems. Stored in read-only memory, it enables key functions such as: 

• Charging – Starts and stops charging sessions.
• Safety – Maintains electrical safety during charging.
• Cybersecurity – Protects against unauthorized access and tampering.
• Communication – Exchanges data with the EV to assess battery status, state of charge, and power needs.
• Updates – Supports software updates for new features and improved compatibility.

Connector/Plug

EVSE connectors play a crucial role in facilitating the transfer of electrical power between the charging station and the electric vehicle. Different connector types are used for various charging levels and charging standards, ensuring compatibility and interoperability across different EV models and charging infrastructure.Here are the common standards:

Level 1 (120V AC, slow charging)

• J1772 – Standard connector for most EVs in North America.
• CCS (Combined Charging System) – Supports Level 1 AC charging.

Level 2 (240V AC, moderate charging)

• J1772 – Standard connector for most EVs in North America.
• CCS (Combined Charging System) – Supports Level 2 AC charging.
• NACS (J3400) – Tesla’s standard connector, also used for non-Tesla EVs at certain compatible stations.

Level 3 (DC Fast Charging, high-power charging)

• CCS (Combined Charging System) – Supports DC fast charging with additional power pins.
• CHAdeMO – Mainly used by Japanese EVs for DC fast charging.
• NACS (J3400) – Supports Tesla Superchargers and other DC fast-charging stations.

These connectors feature robust construction and standardized pin configurations to ensure secure and efficient power transmission during charging sessions.By supporting multiple connector types, EVSE maximizes accessibility and convenience for EV owners, regardless of their vehicle's make or model.

The variety of connector types in EVSE stems from vehicle manufacturers' diverse port connections on EVs. Stations with multiple cable options are often available to accommodate various connectors. Naturally, many EV owners carry adapters on their own for charging at different stations just in case.

Electronics

The electronic components of EVSE play a critical role in managing charging sessions and ensuring efficient power delivery to electric vehicles. The main relay acts as a gateway, controlling the flow of electricity to the vehicle and safeguarding against overcharging or electrical faults. The control module orchestrates the charging process, communicating with the vehicle and monitoring battery health to optimize charging efficiency. A robust power supply ensures stable power output, while dedicated electrical circuits for each charging socket minimize the risk of circuit overload and ensure reliable performance.

Cables

Cables in EVSE serve as conduits, transmitting power from the charging station to the vehicle. They come in flexible or permanently attached options, offering maneuverability or enhanced durability. Ideally, longer cables provide greater convenience, but NEC regulations limit cable length to 25 feet. However, if equipped with a cable management system integrated into the EVSE, the cord length can exceed this limit. These regulations ensure safety and compliance with industry standards for EV charging installations.

Network Connectivity

By integrating WiFi or cellular connectivity, EVSE can communicate with mobile apps or cloud-based charging management platforms, allowing users to remotely monitor and control charging sessions from anywhere. This connectivity enables features such as scheduling charging times to take advantage of off-peak electricity rates, receiving real-time charging status updates and notifications, and accessing historical charging data for analysis and optimization. Network-connected EVSE also enables fleet operators and charging station owners to remotely manage and monitor multiple charging stations, ensuring efficient operation and maintenance.

To further enhance EVSE integration, solutions like the AFE-EVSE SECC Solutions offer advanced control and communication features, simplifying the development of intelligent charging stations.

When you connect your electric vehicle to an EVSE, several steps occur to initiate charging.

Connecting the Charging Cable

When the charging cable is plugged into an EV, the control module analyzes the plug’s connectors to verify a proper connection. It ensures that the vehicle is ready to receive power and that the charging station is functioning correctly. Many EVSE units use status indicators, often color-coded lights, to signal whether everything is in order. If the connection is secure and no issues are detected, the system prepares to initiate charging.

Activating the Charging Process

Once all initial checks are successful, the EVSE activates the main relay, allowing electricity to flow from the charging station to the vehicle. This relay acts as a safety mechanism, preventing power from being transferred until a secure connection is confirmed. At this point, the EV and the charging station establish communication to regulate power flow based on the vehicle’s needs and the charger’s capabilities.

Charging Process (AC vs. DC)

AC Charging (Used in Level 1 and Level 2 Charging)

For AC charging, the EVSE supplies alternating current (AC) power to the vehicle without initial conversion. Since EV batteries store energy in direct current (DC) form, the power must first pass through the vehicle’s onboard charger. This built-in component then converts AC into DC before directing it to the battery.

DC Charging (Used in Level 3 Fast Charging)

In DC fast charging, the EVSE bypasses the onboard charger and delivers direct current (DC) power straight to the vehicle’s battery. Since the EVSE has already converted AC to DC using its built-in converter in advance, this direct approach significantly accelerates the charging process.

Charging Completion & Disconnection

Once the charging process begins, the EV’s battery continues to receive power until it reaches the desired charge level or until the user decides to stop charging. The EVSE and the vehicle continuously communicate to regulate the charge and prevent overloading. When charging is complete, the user can safely unplug the cable from the EVSE, disconnecting the vehicle from the power source. At this point, the charging station resets, ready for the next session.

According to the National Electrical Manufacturers Association (NEMA) and the US Department of Energy, EVSE is classified into three levels based on the voltage and charging capabilities:

Level 1 Charger

Level 1 chargers operate on standard 120-volt AC household outlets, making them the most accessible, budget-friendly, and convenient charging option for EV owners. Most EVs come with a portable Level 1 cord set, meaning no additional charging equipment is required. These chargers typically provide a slower charging rate compared to higher-level chargers. It provides approximately 5 miles of range per hour of charging, so 8 hours of charging can replenish about 40 miles of electric range for a mid-size EV.

These chargers are suitable for residential charging, allowing EV owners to plug their vehicles into standard electrical outlets in garages, driveways, or parking spaces overnight. They are ideal for individuals with limited daily driving needs or those who have ample time for charging. As of 2023, less than 1% of public EV charging ports in the United States were Level 1.

• Charging Speed: 5 miles of range per hour of charging.
• Use Cases: Residential charging, home use, overnight charging.
• Connectors: 120-volt AC plug (CCS, J1772). Suitable for: EV owners with limited daily driving or ample charging time.

Level 2 Charger

Level 2 chargers operate on 240 volts of AC power, offering faster-charging rates than Level 1 chargers even though they adopt the same J17772 connector. These chargers require the installation of dedicated stand-alone charging equipment. Charging an EV for 8 hours with a Level 2 charger can add more or less 200 miles of electric range for a mid-size EV.

These types of chargers are commonly installed in residential settings for faster home charging (multi-family units) or in public charging stations, workplaces, hotels, commercial buildings, and parking facilities. These units require a dedicated 40-Amp circuit to comply with the National Electric Code (Article 625) requirements. They are suitable for EV owners with moderate to high daily driving distances or those who require quicker charging due to their significantly reduced charging times. As of 2023, nearly 80% of public EV charging ports in the United States were Level 2.

• Charging Speed: 25 miles of range per hour of charging.
• Use Cases: Residential (home and multi-family), public stations, workplaces, commercial buildings.
• Connectors: 240-volt AC (CCS, J1772, J3400).
• Suitable for: EV owners with moderate to high daily driving needs.

Level 3 Charger

Level 3 chargers, also known as DC Fast Chargers or DCFCs, operate on high-voltage direct current (DC) power (400- to 900-volts), providing rapid charging capabilities for EVs. These chargers can deliver significantly higher charging rates compared to Level 1 and Level 2 chargers, enabling quick replenishment of EV batteries. With 30 minutes of charging using DC Fast chargers, it can add around 100 to 200 miles of electric range.

There are three types of DC fast charging systems, depending on the vehicle’s charge port: SAE Combined Charging System (CCS), CHAdeMO, and J3400 (only for Tesla models). These chargers are primarily installed in public charging networks, highway rest areas, service stations, and commercial areas where fast charging is essential for long-distance travel or quick turnaround times. As of 2023, over 20% of public EV charging ports in the United States were DC fast chargers, and this number is expected to rise due to federal funding aimed at building a national EV charging network.

DC fast charging options are also substantially pricier, often requiring 10 to 20 times more investment than other chargers due to their complex components and higher power input requirements. That’s why they are recommended for EV owners undertaking frequent long-distance trips or commercial fleet operators requiring rapid charging for multiple vehicles.

• Charging Speed: 100 to 200 miles of range per 30 minutes of charging.
• Use Cases: Public charging stations, highway rest areas, commercial areas, and long-distance travel.
• Connectors: 400- to 900-volt DC plug (CCS, CHAdeMO, J3400)
• Suitable for: Frequent long-distance travelers, and commercial fleet operators.

EVSE comes with a range of features designed to ensure efficient and safe charging for EVs.

Firstly, EVSE often incorporates smart charging capabilities, allowing users to monitor and control the charging process remotely. Smart EVSE systems enable features such as scheduling charging times, setting charging limits, and receiving notifications on charging status via mobile apps or online platforms. This not only enhances user convenience but also enables more efficient use of electricity, particularly during off-peak hours when energy costs may be lower.

Furthermore, safety features are paramount in EVSE design. EVSE systems include built-in features, such as breakaway cables, safety outlets, thermal sensors, and ground fault circuit interrupters, to protect against overcharging, overheating, short circuits, leakage current, and other potential electrical hazards. These safety mechanisms ensure that both the EV and the charging infrastructure remain secure during the charging process.

Finally, interoperability is a key consideration in EVSE design. Compatibility with different EV models and charging standards ensures that EV owners have access to charging infrastructure regardless of their vehicle type or manufacturer. Common charging connectors, such as the SAE J1772 or CCS (Combined Charging System), allow for seamless connection between EVs and the charging stations.

Overall, the features of EVSE contribute to a user-friendly, efficient, and safe charging experience for electric vehicle owners, supporting the transition to a more sustainable transportation ecosystem. With advancements in EV technology, OEMs are positioned to capitalize on new growth opportunities, as highlighted in this news article.

Electric Vehicle Supply Equipment stands at the forefront of the electric mobility revolution, facilitating the widespread adoption of electric vehicles. As we embrace the transition to electric mobility, investing in robust EVSE infrastructure is paramount to realizing a cleaner, greener, and more sustainable future.

Experience the future of EVSE integration with Advantech's comprehensive solution. Our integrated EVSE Controller & SECC Design streamlines manufacturing and maintenance, while enhanced manageability ensures optimal performance even at scale. With scalability in computing and AI capacity, our solution is future-proof, ready to meet evolving demands. Plus, our design-in-service approach prioritizes security, safeguarding your network against cyber threats. Elevate your EVSE charging infrastructure with Advantech today!