ISO 15118 series – A standard for charging station outlets that cannot be ignored anymore

In the design and development process of charging piles in most domestic pile industries, the cost of charging piles, the appearance design of charging piles, as well as the structure (fire/IP/safety distance), performance (current and voltage accuracy), compatibility (adaptation to major car companies), protection functions (emergency stop/fault stop), etc. of charging piles are considered. However, few manufacturers focus on the communication process between piles and vehicles, let alone whether it complies with relevant communication standards. Just be able to start and charge, the rest is not that important.

If the product is only sold domestically, there is no need to worry. In China’s 3C certification, GB/T27930 (Digital Communication Protocol between Off Board Conductive Chargers and Electric Vehicles) is not a mandatory requirement for charging stations to obtain certification.

The European charging station regulations IEC 61851-24 2014/2023 Appendix C clearly stipulate that the high-order communication of DC charging stations must comply with the requirements of DIN SPEC 70121:2014 or ISO 15118-2:2014. Of course, both can also be supported.

The gun head in the national standard has separate CAN+and CAN – signal lines, and the communication method used by the vehicle and the pile is CAN communication. The European standard gun head does not have a CAN line, and the high-order communication between the European standard charging station and the vehicle is achieved by coupling high-frequency signals to the 12V, 1kHz CP and PE lines. This communication method is called Power Line Carrier (PLC) communication.

The development difficulty of the protocol for the European standard charging station based on PLC communication is much greater than that of CAN communication, and there are not many open-source materials available on the market for reference. Therefore, most pile companies directly purchase separate SECC (Supply Equipment Communication Controller) modules, package their own charging information through CAN signals and send it to the SECC module, which then communicates with the vehicle’s EVCC module.

However, purchasing a separate SECC module is only the first step, and proving that this module meets the requirements of DIN SPEC 70121:2014 or ISO 15118-2:2014 in conjunction with the entire pile is a significant expense.

The quotation for a single test of DIN 70121 or 15118 protocol by a certification body is generally over 100000 yuan, with a fixed testing time of a few days, and additional fees will be charged for exceeding the time limit. The workload for testing 15118 will be slightly greater than that of 70121, and the price will be around tens of thousands higher. If both are done, the price will double.

Domestic pile companies can only curse the certification agency for being unscrupulous while paying money, and can only agree to the European CE certificate. Most pile companies choose to only support DIN 70121 for a simple reason: it is cheaper than 15118, and the testing difficulty is lower, with a higher probability of completion within the specified number of days.

In fact, the certification agency that tested this protocol also made a profit unjustly. The simulator for testing this protocol – a drawer sized box paired with an upper computer – costs over a million yuan, approaching the cost of a second tier city apartment, with a hefty annual software maintenance and upgrade fee. The agreement was established by Europe and only their testing plans can be purchased. The certification body also blames the simulator manufacturer for being unscrupulous while paying, otherwise they would not have the testing capability for this project.

Everyone has no choice.

However, the good days have only been a few years.

The European Union issued COMMISSION DELEGATED REGULATION (EU) 2025/656 in June 2025, which supplements and revises REGULATION (EU) 2023/1804 on wireless charging, electric road systems, and hydrogen supply for road transport vehicles. The REGULATION (EU) 2023/1804, released in 2023, is more commonly known as the Alternative Fuel Infrastructure Regulation (AFIR). It is a key policy introduced by the European Union to accelerate the transition to zero emission transportation and address the issue of insufficient infrastructure for alternative fuels such as electricity and hydrogen. Its core goal is to force member states to improve their infrastructure networks for charging, refueling, and other services through legislation, eliminate users’ “anxiety” about range and energy replenishment, and support the large-scale popularization of electric vehicles (EVs), hydrogen fuel cell vehicles (FCEVs), and heavy-duty electric trucks.

Simply put, you only need to know that the EU has released a revised version of the Alternative Fuel Infrastructure Regulation (AFIR), which has full legal effect and is a mandatory requirement directly applicable to all member states.

In summary, public DC piles after 2026 must comply with the requirements of EN ISO 15118-2:2016, and after 2027, all DC piles and mode 3 AC piles must comply with EN ISO 15118-20:2022.

In the charging pile family, the only one that has been spared is the mode 2 AC charging pile. In China, this portable charging pile (IC-CPD) is called portable charging, with a general power of 3.7 kW. The explanation given in REGULATION (EU) 2025/656 is that mode 2 AC piles use PWM, which is sufficient to support ISO 15118-2 or -20, and will not bring any additional value to the end user.

For domestic pile companies, this regulation is not easy. Just after obtaining DIN 70121 certification, it is mandatory to support 15118, which requires support for both 15118-2 and 15118-20. Many companies may not be aware of the differences between DIN 70121, ISO 15118-2, and ISO 15118-20 standards, as well as the purpose of supporting them.

The story needs to start from the beginning.

In early 2010, the joint working group of IEC Technical Committee 69 (TC69) and ISO Technical Committee 22 (TC22) began collaborating to develop the ISO 15118 series of standards, aiming to address the issue of communication standardization between electric vehicles and charging stations,.

Due to too much consideration from the working group and the low work efficiency of European people, the 15118 series standards have been in preparation and have not been officially released yet.

But the market can’t wait any longer. Especially German car giants, they hope to achieve common charging for their electric vehicles as soon as possible and gain market advantages. So, German industry giants joined forces and, within the framework of DIN, extracted some of the relatively mature content discussed in ISO 15118, and developed a German national standard that could be immediately implemented. DIN 70121 was released in 2012 and updated in 2014. DIN 70122:2018 is a testing standard that serves DIN 70121:2014.

However, the 15118 standard arrived late and only officially released its first version in 2013. Its specific application layer standards and testing standards were gradually released in 2014 and 2018. There are a total of five books in the ISO 15118 series, and the relationships between the five books are as follows:

Therefore, DIN 70121:2014 can be seen as a simplified version of the ISO 15118 standard. DIN 70121 only supports DC charging, while ISO 15118-1-5 standards can support both AC and DC charging, as well as TLS encryption, Plug&Charge functionality, and intelligent charging.

In 2022, ISO 15118 released the second generation of charging standards, namely ISO 15118-20:2022 as mentioned earlier. Compared to 15118-2, it also supports TLS1.3 encryption, V-G (transmitting power to the grid), WPT (wireless charging), and ACD (automatic connection device) functions on the original basis. It also has corresponding testing standards:

The birth of DIN SPEC 70121 was originally intended as a transitional solution to ensure the normal operation of the market before the release of ISO 15118. Unfortunately, in the actual communication selection process between the pile and the vehicle, even when both the vehicle and the pile support 70121 and 15118, 90% of the scenarios still rely on DIN 70121.

In addition to the first mover advantage of DIN 70121, for the vast majority of cars and piles, they do not require any advanced functions (TLS/PNC/V-G/WPT, etc.), they only want to be charged simply.

The European Commission has their considerations.

The Directive 2014/94/EU on the deployment of alternative fuel infrastructure was first issued in 2014, when it was not yet a regulation, but rather a directive.

Directive is different from mandatory requirements of regulations, it only specifies the results that need to be achieved, but leaves the way and form of achieving the results to the discretion of member state governments. The directive is not directly effective and requires member states to translate the content of the directive into law within a specified time. For example, the EU’s Directive on Disposable Plastic Products/EU 2023/814 requires member states to regulate the consumption of certain disposable plastic products, but whether to impose taxes, bans, or other measures is up to member states to decide.

The 2014 Fuel Replacement Infrastructure Directive also included requirements for charging points, hydrogen refueling stations, gas filling stations, etc. to be met by 2020 and 2025, but they were too vague, only stating that there should be “appropriate coverage density” without a clear target value. Undoubtedly, this gave European member states a lot of buffer time and freedom, but the results were not ideal. When formulating national policy frameworks, countries have different goals and measures, resulting in fragmented and uneven infrastructure development within the EU. Countries with good development and high popularity of electric vehicles are naturally willing to invest, while countries with average development of electric vehicles are definitely unwilling to build. Spending one’s own country’s taxpayers’ money to make wedding dresses for others is truly unnecessary.

Moreover, in recent years, the development of new energy electric vehicles has been rapid, with China taking the lead. The penetration rate of electric vehicles (trams, plug-in hybrid trams, and extended range trams) has exceeded 50%. Europe is clearly lagging behind by a large margin, and the most direct reason is weak infrastructure, outdated charging conditions, and complex charging operations, which greatly affect people’s travel experience.

The fact that DIN 70121, as a transitional protocol mentioned earlier, has always been regarded as the mainstream of charging is a clear proof.

Therefore, in this context, the European Commission has realized that new energy infrastructure cannot be delayed any longer. Otherwise, not only will we fail to achieve the 2050 carbon reduction target, but we will also fall behind China comprehensively. So in 2023, the 2014/94/EU directive was updated and upgraded to a requirement of Regulation (EU) 2023/1804. The tags are clearly stated in Article 3, and on the TEN-T core network:

In short, the main highways in the EU require charging stations, especially high-power fast charging stations.

After specifying the number and power of detailed charging stations in the 2023 regulation, the European Commission felt that it was not enough. Electric vehicles only need high-power charging stations, and there is also a need for easy-to-use, easy-to-use, and transparent charging stations.

Imagine driving your latest electric car with joy in Europe, charging smoothly in France with convenient QR code payment, fast charging speed, and clear bills.. But after going to Greece, I found that the physical interface of the gun head was old and not compatible with your latest car. I wandered around several charging stations but couldn’t find a suitable charging gun. So you went to Bulgaria, a neighboring country of Greece, where you can insert a gun, but you need to use a POS machine to swipe your card and do not support QR code payment. You were desperate because you did not carry a bank card with you and the remaining battery mileage of the car was less than 20 kilometers. What a terrible experience.

To solve this situation, it is necessary to unify the physical interface and communication protocol of the charging station.

In Regulation (EU) 2025/656 on fuel substitution infrastructure, the focus is on specifying that the physical interfaces of newly installed or refurbished charging stations must comply with the requirements of IEC 62196-2:2022 and IEC 62196-3:2022, followed by the requirements of ISO 15118-2:2016 and ISO 15118-20:2022 as mentioned above.

The reason for choosing not to use DIN 70121 as a communication standard is not difficult to guess.

DIN 70121 is too simple, lacks secure encryption during communication, and does not support PNC (plug and play) function, which increases the burden on end users and is not very convenient. And with the PNC function, users can operate almost without thinking, plug in the gun and don’t worry about anything – no need to swipe the card, no need to scan the code, no need to click on the screen. After charging, the operator will automatically send you the bill details.

And by 2027, all AC and DC piles will support 15118-20 (mainly V-G function), mainly for the overall grid layout. A single new energy electric vehicle may not be a big deal, but if there are 100000 or even millions of vehicles, the stored energy is considerable. If during peak electricity consumption, a portion of the car’s electrical energy is fed back to the grid, it can greatly reduce the burden on the grid without having to deploy so many generators. In the electric valley, excess energy from the power grid can be transmitted to cars without wasting electricity. Charging stations with grid connection capability are particularly important in some remote areas of Europe, where the main power generation methods rely on wind and solar energy. These energy sources are time sensitive and must be stored, otherwise they will be wasted.

In short, from the revised regulations on fuel substitution infrastructure released in 2025, you can clearly feel Europe’s determination and urgency in new energy facilities. Otherwise, it will not be mandatory to implement in early 2026, six months after its release.

Since it is a regulatory requirement, it is not a scare to everyone, but a genuine demand. On the European monitoring website for fuel substitution infrastructure, detailed data is listed, allowing you to clearly and intuitively see the construction progress of each country.

After the regulations were released, European member states have begun to actively respond. France announced in November 2025 that it will provide ecological subsidies for the purchase of private electric vehicles; In November 2025, Germany released a master plan for charging infrastructure by 2030, fully aligning with the European Union Regulation (AFIR) 2023/1804; In Italy, with coupon subsidies, the market share of pure electric vehicles will only soar by 12.2% in 2025. In December 2025, the remote small island nation of Cyprus in Europe is preparing to allocate 4.5 million euros to promote electric mobility.

Major car companies have also started to launch models that comply with 15118-20. The 2026 model of the old school car company BMW iX3 fully supports V-G function; The Hyundai IONIQ, which doesn’t sell well in China, also plans to collaborate and launch a 15118-20 model in 2026; Mercedes Benz’s EQS and Volkswagen’s ID series are also planned.

For domestic pile enterprises engaged in export business, whether you are willing or not, and whether you have the ability to independently develop SECC modules, ISO 15118-2 and 15118-20 are standards that cannot be bypassed for export to Europe.

At present, according to the author’s understanding, there are few pile enterprises on the market that support ISO 15118-2 plug and play charging (PNC mode), and there is almost no bidirectional charging function that supports ISO 15118-20.

Instead of waiting and watching, it’s better to lay out early and seize market opportunities. Like DIN 70121 mentioned earlier, it was widely used a few years ago.