Application Guidance: EVSE (AC)

When selecting EV chargers, several considerations should be taken into account:

• Power output: The chargers should have a power output that aligns with the site’s charging needs, including the size of the EV fleet, the desired charging speed, and the available electrical capacity. An EV charger’s power output may sometimes be specified in amperage. Many commercial EVSE products provide a mechanism through a physical switch or software programming to adjust and limit their maximum power output. DC EVSE products offer higher power output than AC EVSE products (see Technology Basics for more information)
• Connectivity and smart features: Connectivity may be available via Ethernet, Wi-Fi, cellular capabilities, or any combination of the above. Features enabled by connectivity may include remote monitoring, access controls, charging network platform participation, and automatic load management.
• Automatic load management (ALM) capability: ALM requires connectivity to enable communication between chargers at the site. EV chargers within the same ALM group can work in the confines of the site’s electrical capacity and dynamically allocate the available power among the connected EV chargers without overloading the site’s electrical infrastructure.
• Charging network platform compatibility and support: Participating in a charging network platform, a capability enabled by EVSE connectivity, may deliver significant benefits to the EVSE owners and operators. These platforms often provide real-time charging station availability and pricing information, different payment options, and payment processing services, simplifying the charging experience for users. Each EVSE brand and model, however, may have specific partnerships with different charging network platforms.
• Demand response (DR): EVSE can support grid stability and optimize site energy use through participation in demand response programs. In unidirectional configurations (i.e., grid-to-vehicle), EVSE may respond to a DR signal by pausing or reducing charging activity during periods of peak demand or high electricity prices. Utilities and grid operators benefit from these reductions, while site owners may receive financial incentives for participation. For systems with bidirectional power capability (i.e., also vehicle-to-grid), DR participation can also include controlled discharge or energy export events, supplying power from vehicle batteries back to the grid, a building, or local loads during demand peaks. Effective DR participation requires appropriate interconnection agreements, compatible communications protocols, and energy management controls to coordinate charging and discharging while maintaining grid compliance and protecting vehicle battery health.
• Access controls: If the EV chargers will be installed in an area accessible to the general public, access control is an important consideration. EV chargers may provide different access control options. The most common access control is through RFID cards, similar to the keycards used for building or room entrance controls. Other options include mobile apps, typically a capability provided by charging network platforms, or near-field communication (NFC) that utilizes the same mechanism as contactless payment available on mobile phones.
• Charging cable and management system: EV chargers may have options for the charging cable length. Charging cables are typically available in either 18-foot or 25-foot length. Some EV charger models may offer a charging cable management system as an optional accessory for better organizing the long charging cable when not in use.
• Mounting options: Most EV chargers can be installed as wall-mounted or pedestal-mounted stations to suit the specific layout and requirements of the site. Pedestals are typically sold separately from the EV charger unit.