What is Electric Vehicle Supply Equipment (EVSE)?

Electric vehicle supply equipment (EVSE) controls the transfer of electricity from the local power supply to an electric vehicle (EV) so its batteries can recharge safely and efficiently. While electric vehicle supply equipment is the industry’s technical term, common — and very acceptable — names used for EVSE include EV chargers, charging stations, charge points, or charging docks.

When we think of EV charging, our mental picture is an EV connected via a cable to a public charging station or to a box on the wall of a home garage. It looks a lot like connecting a smartphone to a plugged-in charger, only on a much bigger scale. In general principles, it is.

But the universe of EVSE is far more complex. EVSE options range from simple to complex, with multiple form factors, use cases, charging levels, connectors, standards and protocols. So, while it’s perfectly OK to call EVSE an “EV charger,” the term covers a lot of territory.

What are the components of EVSE?

All EV charging stations, from home chargers to high-power public charging stations, have these components:

• Housing or enclosure
• Electronics inside the housing
• Firmware
• Network connectivity (optional)
• Power connection
• Port(s) on the housing and flexible cable(s)
• Connectors on the cable that plug into the EV

Public charging stations also have to have a way to accept payments, such as via mobile apps or hardware options like RFID card readers and charge card readers.

Housing or enclosures

There are several form factors for EVSE housing, ranging from a box on the cable itself to an enclosure mounted a wall or pedestal to the towers you see at public charging locations. The box-on-a-cable is primarily for home charging. Wall- and pedestal-mounted devices can be for home, multi-family residential, workplace, fleet, hotel, retail, or public chargers. Towers are typically found at public and fleet depot locations with multiple charging stations.

Electronics

At minimum, an EV charger consists of the main relay, which turns the power flow to the vehicle on or off, a control module that manages the relay and the charging session, a power supply that powers the control module and the relay, an electrical circuit for every charging socket (port) or fixed cable attachment, and optionally some kind of user interface like an LCD screen.

Firmware

Firmware is microcode or software that is embedded into the read-only memory in a hardware device like the controller or the network card in EVSE. Firmware enables these components to operate and communicate with other software running on a device, including software in the EV or the firmware in the network card or an EVSE’s LCD display. The EVSE controller firmware provides a number of functions, including starting and stopping the charging session, ensuring electrical safety, providing cybersecurity protection, and communicating with the EV to determine condition of the battery, state of charge, and amount of power required. Firmware can be updated to provide new functions or extend compatibility with different EV brands and models.

Network connectivity

Smart EV chargers are additionally equipped with a WiFi or cellular network connector for communications between the charger and a mobile app or the back-end EV charging management system in the cloud, or both. For home smart chargers, connectivity allows the EV owner to start, stop, and schedule charging and take advantage of time-of-use tariffs to reduce costs.

Power connection

Home EV chargers can plug into either standard 120-volt household outlets (Level 1 charging) or 240-volt (Level 2 charging) outlets (the service typically used for electric stoves or dryers). Level 2 chargers can also be hardwired directly into 240V household service or 208v commercial service. Multi-charger private and public installations (Level 2 or Level 3) are hardwired to electrical service infrastructure installed specifically for EVSE, which is in turn connected to the grid.

Ports and cables

Ports are the receptacles on the EVSE housing that cables attach to. Cable can also be permanently connected to the housing. Cables themselves are flexible conduits for electricity.

Connectors

At the other end of the cable is the connector that plugs into the port on the EV. Here’s where it gets a little complicated. The type of connector used depends on the level and type of charger, whether it outputs AC or DC electricity, and what connector standard the EVSE supplier or EV charging service provider (EVSP) is supporting, and where you’re located. Here’s a brief summary of EVSE levels, speeds, output, and connectors they use:

• Level 1 charging: 120-volt AC
  Connectors: None or J1772
  Charging speed: Up to 20 hours for full charge (slow)
  Use cases: Home charging
• Level 2 charging: 208- to 240-volt AC
  Connectors used: J1772 or combination (CCS, NACS, CHAdeMO)
  Charging speed: 5 to 6 hours for a full charge (faster)
  Use cases: Home, work, multi-family unit, hotel, retail, fleet, public charging
• Level 3 charging: 400- to 900-volt DC
  Connectors used: CCS, NACS, CHAdeMO
  Charging speed: 30 — 45 minutes (fast) or 15 minutes (ultrafast), which is why these chargers are often called Direct Current Fast Chargers (DCFC)
  Use cases: Public charging

AC, DC, and EVSE: What happens where?

At this time, all power grids distribute AC (alternating current) electricity to consumers and businesses, although the frequency varies by location and voltage varies by type of service. All batteries, including disposable and rechargeable batteries — from tiny coin batteries in hearing aids to utility-scale power storage units, receive and output DC (direct current) electricity.

So, for recharging your smartphone or your EV, AC has to be converted to DC. For Level 1 and Level 2 EV charging, the AC-to-DC conversion is handled inside the EV by its onboard charger. Level 3 DC fast chargers, on the other hand, are equipped with converters in the EVSE housing to change grid-supplied AC to high-voltage DC output. For EV charging, the DC power bypasses the EV’s onboard charger and goes directly into the batteries.

In closing: Software considerations for smart EV charging management

Organizations that are providing non-home smart EV charging, whether it’s a few Level 2 chargers at a few locations or thousands of Level 2 and Level 3 chargers across the country, will need EV charging management software. When choosing this software, look for a future-proof, scalable solution that offers brand-agnostic support for all EVSE types and configurations, smart monitoring and control features that enable operational excellence, smart energy management, and support for industry standards and protocols.

What Is EVSE, Really?

Electric Vehicle Supply Equipment (EVSE) is a less-common term for charging stations or charging docks for electric vehicles. Even though “charging station” is more common and easily understood, EVSE is actually more accurate to all the components that make up the system.

The National Electronics Manufacturers Association (NEMA) defines EVSEs as:

“Devices that provide electric power to the vehicle and use that to recharge the vehicle’s batteries. EVSE systems include the electrical conductors, related equipment, software, and communications protocols that deliver energy efficiently and safely to the vehicle.”

So calling an EVSE a “charger” isn’t totally accurate in the way you might think of a phone charger. EVSEs aren’t simply plugs or cords, but there are different protocols, software, and equipment that allows the entire system to work effectively to charge an EV car and keep everything safe.

The Components Of EVSEs

So, EVSEs aren’t just a cord. They have multiple components that make up the entire charging system, but what are those components? The three main components of an EVSE are:

• The software

• The enclosure

• The plug

Software: Makes Everything Run 💾

The software in an EVSE makes sure everything runs smoothly, and it includes communications protocols. Most of the behind-the-scenes details that ensure the charging cord is properly connected to the car, the car is ready to charge, and the charging station is in working order are all handled by software.

One of the most recent and helpful upgrades in the world of EV software is called Open Charge Point Protocol (OCPP).

OCPP is an application protocol— a structure that allows completely different programs to interact with each other. (Think about pairing a Bluetooth speaker to your cell phone.)

OCPP allows communication between EV charging stations and their central management system, which provides a way for charging stations to function alongside management systems from different vendors (something that is becoming more and more prominent as more manufacturers enter the EV space).

Enclosure: Holds The Power Supply 📦

The enclosure of an EVSE can look different depending on the type, but you’ll commonly see wall mounts or towers at public places like gas stations or hotels. The enclosure holds the power supply, the main relay which switches power to the vehicle, and the control module that manages the main relay.

Plug: Connects The EVSE To The Car 🔌

Even though the plug may seem like the most simple and straightforward aspect of an EVSE, it can actually be the most confusing part sometimes. This is because different charging stations use different plug connectors.

The plug is usually determined by the region and the level of the station (more on that later). Since plugs can be so different across the board, some EVSE manufacturers build charging stations with a variety of connector types. Plus, EV owners commonly carry adapters with them while on the road.

Features & Perks Of EVSEs

Electric Vehicle Supply Equipment is pretty impressive— the equipment is designed and engineered to keep you, your car, your home, and the charging system safe during the recharging process. There are numerous safety and convenience features on EVSEs, including:

• • Automatic disconnect when a hardware fault is detected (avoids risks like battery damage, electrical shorting, or fires)

  • Auto-restart after power outages

  • Auto short circuit and ground fault shut-off

• Breakway safety cables

• • Conforms to The Society of Automotive Engineers’ requirements

  • Enclosures meet the NEMA standards for user safety

  • Ground fault monitors eliminate the need for monthly user testing

• Integrated cable storage

• Power-sharing senses other large electrical loads in use in your house and pauses EV charging til the load is lessened

• Regulated electrical current ensures the optimal current is used that falls within the maximum current the car can handle

• Safety lock-out features prevent the electrical current from overflowing when the charger isn’t connected to the vehicle

• Safety outlets ensure the car’s connection cable is properly and completely inserted before power will begin flowing

That’s a lot of incredible safety features and perks that ensure everything is in working order when using an EVSE system. Whether you use an EVSE at home or on the road, reputable manufacturers construct them with safety and ultimate performance in mind.

Different Types Of EVSE Systems

EVSE systems were not created equally, just like how electric vehicles weren’t. Although it would be convenient if all EVs and EVSEs were exactly the same, a competitive market keeps that from happening.

There are three descriptors that make up a specific type of EVSE: mode, level, and type. But before we dive further into those factors, we need to touch on AC and DC electric power.

In this case, AC and DC power aren’t a world-famous rock band but different kinds of electrical currents used when charging EVs. While traditional vehicles use gas for fuel, EVs use AC or DC power.

• Alternating Current (AC): The power that comes from the grid is always AC. Electricity in homes and businesses runs on AC power. Most EV charging stations use AC power, but it needs to get converted into DC power to feed the car’s battery.

• Direct Current (DC): DC power was actually the first type of electricity developed by Thomas Edison. DC power is an electric current that constantly runs in one direction. It’s the same type of power found in solar cells and batteries. DC chargers for EVs are bigger, faster, and can feed power directly to the car’s battery without a separate converter.

Mode

The mode is how the EVSE connects to the electrical grid. There are four modes an EVSE could have:

• Mode 1: Plugs into a household AC socket but is generally not permitted in most regions because it lacks special safety considerations.

• Mode 2: Also plugs into a standard household AC outlet but includes safety features in an in-cable control box (ICCB).

• Mode 3: Plugs into a charging station or wall box for an AC charge and doesn’t include an ICCB. European EV owners often have to bring their own Mode 3 cable to use public charging stations.

• Mode 4: Reserved for high-speed DC charging at charging stations.

Level

EV charging levels are commonly used as descriptors for charging stations. The level indicates how much electric power is delivered to the vehicle during charging. The levels are:

• Level 1: 120V (volts) and 1.8kW (kilowatts). Delivers the most basic, but slowest, charge. The most common charger in homes.

• Level 2: 240V. Most homes have 240v outlets to power larger appliances. Level 2 chargers are twice as powerful and faster than Level 1.

• Level 3 (or DC 1 and 2): 480V and more than 350kW. Level 3 AC charging is technically DC level fast charging. It is the fastest way to charge an EV, but it’s the least common.

Type

Last but not least, we have the type. The type refers to the vehicle interface, and unfortunately, there is no global standard type. There are unique interfaces for AC charging based on location:

• North America and Korea: J1772 Type 1 for AC charging and CCS1 for DC charging

• Europe: IEC Type 2 for AC and CCS2 for DC

• Japan: J1772 Type 1 for AC and CHAdeMO for DC

• China: GB/T for AC and a unique DC interface

Tesla models of EVs have their own unique type of interface. Reference this chart to see what each type looks like:

Need EVSE Help? Count On RuiHua

EVSEs are pretty incredible systems that allow more and more people to make the switch to electric energy and away from traditional fuel. If you’re ready to make the switch to an electric vehicle, the knowledgeable team at RuiHua can help install an EVSE for your home.

We’ll help you understand the different types of charging stations, power sources, and adapters so that you never feel unprepared before hitting the road.

Contact us today with any questions or to set up a free consultation!