| Output Power | Rated DC charging power and power-sharing capability | Common public configurations include approximately 20–60 kW for destination charging, 60–180 kW for routine public charging, and 180–350 kW for high-power corridor charging. | Higher power can reduce charging time, but the vehicle, electrical connection, battery temperature, and state of charge may limit the actual power received. | Select power according to site dwell time, grid capacity, vehicle mix, and expected utilization rather than choosing the highest rating alone. |
| Electrical Safety | Overcurrent, overvoltage, short-circuit, surge, insulation, and ground-fault protection | Look for protection designed and tested according to applicable requirements such as IEC 61851, IEC 62955, IEC 60364, and local electrical codes. | DC chargers connect high-voltage power electronics directly to vehicle batteries, so fault detection and controlled shutdown are essential. | Require documented protection functions, test reports, emergency-stop provisions, and a clearly defined protective-earthing arrangement. |
| Residual Current Protection | Detection of AC and smooth DC residual currents | Depending on the charger design and local code, protection may use a Type B residual-current device or a Type A device combined with 6 mA DC residual-current detection. | DC leakage can reduce the effectiveness of some upstream protection devices and create additional shock and fire risks. | Verify the complete protection architecture with a qualified electrical professional; do not select a device based only on an RCD label. |
| Thermal Management | Temperature monitoring, cooling method, and derating behavior | Air cooling is common for moderate power. Liquid-cooled cables or power modules may be used for sustained high-power operation. Chargers should reduce output safely when temperature limits are reached. | Heat accelerates component aging and may reduce charging performance, especially in hot climates or heavily used sites. | Choose temperature sensors on power modules, connectors, cables, and key internal points, with automatic derating and fault logging. |
| Ingress and Impact Protection | Outdoor enclosure sealing and mechanical resistance | IP54 or higher is commonly considered for protected outdoor equipment; higher ratings may be appropriate for exposed locations. IK10 is a common target for impact-resistant public equipment. | Water, dust, ice, salt, and vandalism can cause insulation faults, corrosion, and unplanned downtime. | Match the enclosure rating to the installation environment and confirm that cable entries, doors, displays, and connectors maintain the stated protection level. |
| Charging Communication | Vehicle-to-charger communication and interoperability | Confirm support for the applicable DC charging communication method, connector standard, and regional requirements. ISO 15118 may enable advanced functions such as Plug & Charge where supported. | Interoperability affects which vehicles can charge reliably and whether future digital services can be added. | Request test evidence with the target vehicle population and verify compatibility with the intended connector and communication standards. |
| Smart Controls | Remote monitoring, load management, tariff control, and user authorization | Useful functions include dynamic load balancing, scheduled charging, remote start and stop, user authentication, energy metering, and firmware management. | Smart controls help reduce peak demand, coordinate multiple chargers, and improve operational visibility. | Prioritize open interfaces and role-based access rather than relying on a closed system with limited integration options. |
| Backend Connectivity | Network protocol, remote diagnostics, and data availability | OCPP 1.6J remains widely deployed, while OCPP 2.0.1 provides newer capabilities for device management, security, and transaction handling. Cellular, Ethernet, and Wi-Fi may be used depending on site conditions. | Reliable data exchange supports payment, status monitoring, troubleshooting, and fleet or energy-management integration. | Confirm protocol version, supported profiles, offline operation, data ownership, API access, and secure certificate management before purchase. |
| Cybersecurity | Authentication, encryption, secure updates, and event logging | Look for encrypted communications, unique credentials, signed firmware, secure boot where available, account separation, vulnerability handling, and audit logs. | Connected chargers are networked energy assets and can affect billing, site operations, and electrical load control. | Request a documented cybersecurity process, update policy, credential policy, incident-response procedure, and supported security lifecycle. |
| Metering and Billing | Energy measurement accuracy, transaction records, and display information | Use a meter appropriate for the intended billing and regulatory application. For revenue-grade use, confirm local metrology approval, sealing, calibration, and applicable accuracy requirements. | Accurate energy records are necessary for transparent billing, customer support, and energy-cost analysis. | Separate general monitoring meters from legally controlled billing meters and verify local legal-metrology requirements before deployment. |
| Reliability Design | Power-module architecture, component quality, redundancy, and environmental ratings | Modular power stages, replaceable modules, conservative thermal design, corrosion protection, and event-level fault records can improve serviceability and uptime. | A single failed module should not necessarily disable an entire multi-module charger. | Compare warranty terms, rated operating temperature, humidity limits, altitude limits, expected duty cycle, and documented uptime methodology. |
| Cable and Connector Durability | Cable cooling, strain relief, connector locking, and replacement process | Check cable bend radius, connector protection, temperature sensing, locking behavior, and availability of replaceable cable assemblies. | Cables and connectors are frequently handled and are among the most exposed parts of a public charging system. | Choose a design with accessible inspection points, replaceable wear parts, and clear cable-management provisions to limit ground contact and vehicle impact. |
| Maintenance Requirements | Preventive inspections, filters, cooling systems, and spare parts | Maintenance may include visual inspection, connector cleaning, torque checks, thermal inspection, firmware updates, filter replacement, and cooling-system servicing where applicable. | Predictable maintenance reduces emergency repairs and helps maintain charging performance over the service life. | Obtain a maintenance schedule, diagnostic software access, spare-parts list, technician training plan, and target response times. |
| Serviceability | Remote diagnosis, modular replacement, access control, and repair documentation | Preferred features include component-level alarms, remote log collection, guided fault codes, front or rear service access, and replaceable power modules. | Fast fault isolation can reduce site visits and shorten downtime. | Evaluate mean time to repair, remote-resolution capability, parts lead time, local service coverage, and whether repairs require specialized tools. |
| Installation and Grid Impact | Input voltage, maximum demand, harmonics, power factor, and protection coordination | Confirm compatibility with the site's available supply, transformer capacity, switchgear, cable sizing, and local power-quality limits. Power factor correction is commonly used in modern high-power equipment. | A charger can be technically capable yet unsuitable if the site cannot safely supply its maximum demand. | Complete a load study and protection-coordination review before final selection; include future expansion in the design. |
| Total Cost of Ownership | Purchase price, installation, energy losses, network fees, maintenance, and downtime | Compare efficiency, standby consumption, warranty coverage, service contracts, replacement parts, software fees, and expected utilization over the planned service period. | The lowest initial price may result in higher operating costs or more lost revenue if reliability and support are weak. | Use a multi-year cost model that includes electricity demand charges, maintenance labor, spare parts, software, and the financial impact of unavailable ports. |
