Global EV sales reached about 21M in 2025, up from roughly 17M in 2024, according to the IEA's Global EV Outlook 2026 report [1]. With one in four new cars sold worldwide being electric and demand for electric vehicles (EVs) soaring, EV infrastructure should keep up. More vehicles mean more chargers, and those chargers carry significantly greater responsibility than they did a few years ago. Today they must be safe, interoperable, secure by design, and compliant with a growing body of regulation. EV charging station testing is how you get there.
Testing an EV charger ensures safety, efficiency, and compatibility with different EV models. There are also three business reasons it matters:
- Lower development costs. Testing throughout development catches critical errors and efficiency bottlenecks early, which cuts operational expenses.
- Faster time to market. Finding and fixing issues quickly lets you launch sooner.
- Regulatory market access. In the EU, new ISO 15118 and cybersecurity requirements now determine whether a charger can be sold and installed at all.
Let's explore how to test EV charging stations effectively and how N-iX's expertise in automotive testing and EV charging station testing can help.
Executive summary:
- EV charging station testing spans six key areas: Functional performance, electrical safety, cybersecurity, interoperability, performance testing, and compliance. Covering the entire charging system helps detect failures early and reduce risks before deployment.
- OCPP and ISO 15118 testing address different communication interfaces. OCPP validates charger-to-backend interactions, while ISO 15118 testing covers vehicle-to-charger communication, including Plug & Charge and supported bidirectional charging functions.
- Regulatory requirements shape EV charger testing strategies. In the EU, AFIR phases in ISO 15118-2 (from January 2026) and ISO 15118-20 (from January 2027) for new or renovated charge points, while US NEVI rules set OCPP and ISO 15118 requirements for covered infrastructure. Cybersecurity requirements also vary by market.
- Reliable charging depends on testing across connected hardware and software. Combining automated QA, embedded engineering, protocol testing, and cloud validation helps identify integration issues that individual component tests may miss.
Key steps of EV charging station testing
EV charging stations should be tested at various levels, with compliance becoming a testing discipline in its own right.
1. Functional testing
This stage evaluates the charger’s core functions. Can it start and stop a charging session, communicate with the vehicle, operate at different power levels, and handle interruptions and errors? For chargers that support bidirectional charging, testing also covers reverse power flow and transitions between charging and discharging.
2. Safety testing
Safety testing verifies protection against electric shock, overheating, and electrical faults. Depending on the charger design, it covers insulation, protective grounding, residual current protection, and safe shutdown under abnormal conditions. In Europe, EN IEC 61851-1 defines general safety requirements for conductive EV charging equipment.
3. Security testing
Security testing identifies vulnerabilities that could compromise charging operations, sensitive data, or connected systems. Our experts assess hardware, firmware, software, and communication interfaces.
Typical checks at this stage include:
- Secure boot and firmware integrity;
- Authentication and encrypted communication;
- Secure firmware and software updates;
- Credential and certificate management;
- Penetration testing of supported communication interfaces.
Security assessments also provide evidence for compliance with applicable cybersecurity regulations.
Explore further: EV charging management software: Main security risks
4. Interoperability testing
Interoperability testing verifies that a charger works with different vehicles, back-end systems, and charging networks. This includes testing supported OCPP versions (1.6, 2.0.1, and 2.1) for back-end communication and ISO 15118 standards (-2 and -20) for vehicle communication. US-focused testing should also cover applicable CCS1 and J3400 (NACS) charging interfaces. Combining protocol simulators with real-vehicle testing helps identify compatibility issues that standardized test cases may miss.
5. Performance testing
Performance testing measures charging speed, energy efficiency, power output, and metering accuracy under different operating conditions. It also evaluates power stability during extended operation.
Reliability matters particularly for public charging infrastructure. For example, under the US National Electric Vehicle Infrastructure (NEVI) program, each charging port must maintain greater than 97% average annual uptime [2]. Meeting this metric requires post-deployment monitoring alongside pre-deployment reliability testing.
6. Compliance and certification testing
This stage brings together evidence from the preceding tests to demonstrate conformity with applicable industry standards and market requirements. Depending on the charger and its target market, it may include electrical safety and EMC assessments, ISO 15118 conformance testing, preparation for OCPP certification, and cybersecurity compliance. Laboratory testing, simulation, and field validation complement one another, while formal certification follows the relevant certification body's procedures.
Two communication protocols deserve particular attention because they govern how chargers interact with vehicles and management systems.
Communication standards behind EV charger testing
Two key standards enable interoperability between EVs, chargers, and Charging Station Management Systems (CSMS):
- OCPP (different versions): communication between the charger and CSMS;
- ISO 15118 (different versions): communication between the EV and the charger.
Both are now referenced in regulations, making them central to automotive software development and testing.
OCPP for EV charging station testing: What to verify across protocol versions
The Open Charge Point Protocol (OCPP) defines how charging stations communicate with CSMSs. It enables operators to monitor chargers, manage sessions, process transaction data, and remotely control charging infrastructure.
Three protocol versions are relevant in 2026:
- OCPP 1.6 remains widely used across existing charging networks;
- OCPP 2.0.1 adds improved security, device management, transaction handling, and smart charging capabilities;
- OCPP 2.1, released in January 2025, extends these capabilities with bidirectional charging support, distributed energy resource management, and additional payment options.
As charging networks adopt newer versions, manufacturers must validate compatibility with the protocols their customers use. This may require testing several OCPP versions, depending on the supported implementation.
At N-iX, we assess OCPP implementations through the following testing activities.
1. Connectivity and initialization
Our engineers verify that charging stations establish a stable connection with the CSMS and complete registration. In OCPP 2.0.1, this involves testing the WebSocket connection and boot notification exchange, through which the charger provides identification details and receives a registration response. We also simulate connection failures and reconnection attempts to assess communication stability.
N-iX case study: For a leading EV charging network, we manage communication and operations for all stations connected to the client’s cloud platform across the USA, Canada, Australia, and the EU. Stations reach the platform through a gateway that handles direct socket communication and an OCPP server that translates the industry-standard protocol. A separate message processor then handles the translated station messages.
2. Authorization and charging transactions
We test how chargers authorize users and manage charging sessions, covering RFID cards, mobile-app workflows, and supported local and remote commands. Our team simulates rejected credentials, interrupted sessions, and emergency stops to verify that the charger responds correctly and reports transaction events and charging status to the CSMS.
3. Metering and transaction data
Our specialists assess how accurately chargers transmit energy readings, timestamps, and transaction records to the CSMS. We check for missing, duplicated, or inconsistent data that could affect billing and usage reporting. OCPP 2.1 also supports local cost calculation and additional payment options, which require testing when implemented.
N-iX case study: For a leading energy technology company, we developed EV charging compensation features that collect session data, recalculate costs, and automate tariff updates. The solution also connects the charging app, third-party services, and the energy platform. Accurate charging data helps ensure users receive the correct monthly compensation.
4. Firmware updates, diagnostics, and fault handling
We validate firmware update workflows, including secure downloads, integrity checks, installation status reporting, and recovery from failed updates. Our engineers simulate hardware faults, power interruptions, and connectivity failures to assess how chargers detect, report, and recover from errors. During network outages, we evaluate how charging sessions are handled and whether stored transaction data is synchronized after reconnection.
N-iX case study: For a global EV charging network, N-iX helped develop a centralized fault monitoring service that detects potential issues using station data and system messages. For example, rising charger temperatures can trigger early warnings, allowing maintenance teams to address problems before they cause downtime.
5. Security testing
At this stage, our experts:
- Verify secure connections between the charger and the management system;
- Check certificate validity, expiration, and trust chains;
- Test authentication and protection against unauthorized access;
- Conduct penetration testing to identify vulnerabilities in OCPP communication;
- Assess how the charger responds to simulated cyberattacks.
Security testing is especially important when upgrading older charging infrastructure. OCPP 2.0.1 certification requires TLS-based communication, while some older implementations may still operate without it.
N-iX case study: For a global EV charging network, N-iX built an AWS environment for secure data storage, processing, and analysis. We also implemented over-the-air (OTA) firmware updates protected by encryption and authentication.
6. OCPP certification and version compatibility
We use official OCPP conformance test cases to identify implementation issues and help manufacturers prepare for certification. The Open Charge Alliance operates independent certification programs for OCPP 1.6 and 2.0.1. In October 2026, it also made OCPP 2.1 testing available [3].
For charging networks using multiple versions, our engineers assess compatibility with supported back-end systems and test protocol migration scenarios. Particular attention goes to OCPP 1.6, which is incompatible with newer versions at the protocol level and requires separate implementation support.
ISO 15118 for EV charging station testing: What to verify in vehicle-to-charger communication
While OCPP connects chargers with management systems, ISO 15118 governs communication between EVs and charging stations. It supports features such as Plug & Charge, which allows drivers to authenticate and authorize charging automatically through contract-based credentials.
Two generations are particularly relevant:
- ISO 15118-2 supports charging communication and Plug & Charge;
- ISO 15118-20 introduces advanced charging control, bidirectional power transfer, and enhanced security.
Here's what ISO 15118 testing should cover and what we at N-iX do for that.
1. Connection and communication
Our engineers verify that the charger recognizes a connected vehicle and establishes communication successfully. We test data exchange between the EV and charger, including protocol version negotiation and connection setup.
2. Plug & Charge authentication and security
We test how chargers process Plug & Charge credentials, validate digital certificates, and authorize charging sessions. Our specialists also assess encrypted communication and responses to expired or invalid credentials. For ISO 15118-20 implementations, we verify updated security requirements and, where supported, multiple-contract handling.
3. Charging parameter negotiation
Our team tests how vehicles and chargers negotiate charging parameters, including power, voltage, current, and operating limits. We verify that the agreed settings remain within both systems' capabilities and that charging responds correctly to changing conditions.
4. Bidirectional charging and advanced control
For chargers supporting ISO 15118-20 bidirectional charging capabilities, we test power transfer in both directions, including transitions between charging and discharging. Our engineers also assess scheduled and dynamic charging modes, particularly how chargers respond to changing power limits and setpoints. Where supported, we test wireless charging communication.
5. Error handling and recovery
We simulate connection losses, authentication failures, and incompatible charging settings to evaluate how chargers handle abnormal conditions. Our engineers check whether the charger detects communication errors, responds safely, and restores communication when possible.
6. Compatibility between ISO 15118 versions
For chargers supporting both ISO 15118-2 and ISO 15118-20, we verify compatibility with vehicles using either version. Our specialists focus on protocol negotiation, encryption settings, and certificate handling to identify interoperability issues that individual conformance tests may miss.
EV charger testing must also account for the regulations of its target markets. Let's briefly review the major requirements in the EU and US, particularly for communication standards and cybersecurity.
EV charger testing requirements in the EU and US
Technical testing verifies that a charger works as intended. Regulatory compliance determines which requirements it must meet to deploy in a particular market. For manufacturers, this means identifying applicable standards early, planning the required assessments, and collecting evidence throughout development.
European Union
The EU's Alternative Fuels Infrastructure Regulation (AFIR), updated by Regulation (EU) 2025/656 , introduces phased interoperability requirements:
- From January 8, 2026: New or renovated public charging points must comply with EN ISO 15118-2 and related standards.
- From January 1, 2027: New or renovated public charging points and private Mode 3 and Mode 4 charging points must comply with ISO 15118-20.
- Plug & Charge: New or renovated public charging points offering automatic authentication from 2027 must comply with both ISO 15118-2 and ISO 15118-20 [4].
AFIR also requires specified payment options, including card payments at qualifying public chargers rated at 50 kW or more.
United States
US charger testing must account for supported CCS1 and J3400 (NACS) connections. For infrastructure covered by federal National Electric Vehicle Infrastructure (NEVI) rules, 23 CFR § 680.108 establishes additional requirements:
- OCPP 2.0.1 for communication between chargers and management systems.
- ISO 15118-2 software conformance, including Plug & Charge capability, and hardware capable of implementing ISO 15118-2 and ISO 15118-20 [5].
Additional federal requirements address network interoperability, payment accessibility, and charging port uptime.
Cybersecurity requirements
In the EU, applicable connected radio equipment has been subject to Radio Equipment Directive (RED) cybersecurity requirements since August 2025. The Cyber Resilience Act (CRA) introduces broader product security obligations, with its main requirements applying from December 2027.
In the US, NEVI requires states and other direct funding recipients to implement cybersecurity strategies, with specific measures determined through deployment plans and project requirements.
For manufacturers targeting both markets, security testing should produce evidence of secure communication, access controls, firmware protection, and vulnerability management. These checks help demonstrate compliance with applicable requirements and reduce security risks throughout the charger's operational life. Here's how N-iX software engineering services can help you achieve that.
How N-iX can help with EV charging station testing
Charger issues span hardware, firmware, communication protocols, cloud, and applications. So, EV charging station testing must cover all of them. With over 24 years of experience in software development, 100 delivered IoT and embedded projects, and EV charging solutions used in the US, the EU, and the UK, N-iX works across the full charging stack.
Our capabilities include:
- Software testing and quality assurance. Our 150+ QA professionals help develop test strategies, build test environments, and perform functional, integration, performance, and regression testing across EV charging systems.
- QA automation. We build automated test frameworks and integrate them into CI/CD pipelines to validate charging workflows, protocol interactions, and software updates with every release.
- Embedded software and firmware engineering. Our engineers test firmware behavior, hardware-software interactions, connectivity, and fault handling. We also support hardware-in-the-loop testing and validation of OTA updates.
- Internet of Things development and connected device engineering. We help verify communication between charging stations, CSMS, connected vehicles, gateways, and backend systems, including connectivity failures and data exchange across different configurations.
- IoT cybersecurity. Our specialists assess device authentication, encrypted communication, firmware integrity, and software vulnerabilities to help protect connected charging infrastructure.
- Cloud and back-end engineering. We develop and test charging management platforms, APIs, data pipelines, and integrations. This helps verify that charging sessions, metering data, payments, and diagnostic events are processed correctly.
- Compliance and certification support. We help prepare test environments, execute applicable conformance tests, and document results against relevant technical standards, including OCPP and ISO 15118.
N-iX combines these capabilities with an IoT and Embedded R&D lab for prototyping and automated testing. Our experience with charging network platforms, secure OTA updates, and fault monitoring helps clients identify integration issues before deployment and improve the reliability of systems already in operation.
Wrap-up
Reliable EV charging starts with thorough testing across hardware, software, communication protocols, and security. N-iX combines [professionals] specialists with dedicated QA, embedded engineering expertise, and hands-on EV charging experience. We help manufacturers and network operators identify faults early, improve reliability, and meet market requirements.
Whether you're considering EV charger development or improving an existing charging network, talk to our experts about how we can support your EV charging station testing needs.
FAQ
Can an EV charger be tested for issues?
Yes. EV charging station testing can detect hardware faults, software errors, communication failures, and safety risks before and after deployment. Engineers use diagnostic tools, simulations, automated tests, and real-vehicle testing to identify issues affecting charging performance, security, and reliability.
How often do EV chargers need testing?
EV chargers should be tested during development, before deployment, and periodically throughout operation. Additional testing is recommended after firmware updates, hardware repairs, or major configuration changes. Routine inspection frequency depends on the charger type, usage, operating environment, manufacturer recommendations, and applicable regulations.
What are the main types of EV charging station testing?
The main types include functional, safety, security, interoperability, and performance testing. Compliance and certification assessments also help manufacturers demonstrate that their chargers meet applicable industry standards and market requirements.
How is EV charger interoperability tested?
Engineers test whether chargers communicate correctly with different vehicles, charging management systems, and networks. This includes validating OCPP and ISO 15118 implementations, checking supported connector interfaces, and running charging scenarios with simulators and real vehicles.
What is the difference between OCPP and ISO 15118 testing?
OCPP testing focuses on communication between the charging station and its backend management system, including authorization, transaction reporting, and remote management. ISO 15118 testing verifies vehicle-to-charger communication, including Plug & Charge authentication, charging parameter negotiation, and supported advanced charging capabilities.
References:
- Global EV Outlook 2026 | IEA
- Information on publicly available electric vehicle charging infrastructure locations, pricing, real-time availability, and accessibility through mapping | NEVI
- New milestone: OCPP 2.1 testing is now available | Open Charge Alliance
- Delegated regulation - EU - 2025/656 | EUR-Lex
- § 680.108 Interoperability of electric vehicle charging infrastructure | NEVI
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