Frequently Asked Questions

In this section you will find answers to questions which have been posed by journalists, politicians and representatives of associations and public organizations during the last years.

The answers shall help you better understand the open, universal, internationally standardized charging system for electrical vehicles. The answers are based on experience of our member's experts.

The FAQ section will be reviewed on a regular base and updated if necessary. The information in this area are not legally binding and they do not replace any standard.

Definition of the Combined Charging System (CCS)

CCS history

The Combined Charging System is evolving to the leading charging solution worldwide. Across all branches of industry, the automobile industry, energy suppliers and the electronics industry support the implementation and establishment of a standardized solution for the charging of electric vehicles based on the Combined Charging System.

The EU directive on the development of infrastructure for alternative fuel of 2014 established CCS as the required minimum equipment as of 2017.

The association of European automobile manufacturers selected the Combined Charging System as the future standard interface for all electric vehicles. The ACEA confirmed in a position paper that ALL new electric vehicles will have to implement the Combined Charging System by the end of 2017 at the latest.

This is underpinned by the agreement to use Type2 and Combo2 connectors in Europe that are based on the CCS AC/DC charging interfaces which are compliant to the EU directive.

The Combined Charging System is also seen in the USA as an obvious extension to the existing AC charging standard. Accordingly, SAE, the international association of automotive engineers, completely subscribes to the Combined Charging System.

CCS was selected in October 2012 as the SAE solution for the charging of electric vehicles.

What is the Combined Charging System?

The Combined Charging System (CCS) is an open, universal and international charging system for electric vehicles based on international standards. It provides the solution for all charging requirements.

The Combined Charging System is therefore ONE system for ALL.

The CCS combines single-phase with fast 3-phase AC charging using alternating current of maximum of 43 kW. It also provides very fast high-power DC charging (up to 450 kW) within a single system. Members are presently also working on a High Power charging connector for commercial vehicles that can take multiple MW charging power. This extended High Power charging will be used for speciality EV like busses, truck, etc. ...

The CCS system includes the connector, the managing of control functions and the charging communication between electric vehicle and infrastructure.

What are the other standards?

There are two other standards - CHAdeMO standard developed by the Japanese manufacturers and GB/T standard mandated by the Chinese government for vehicles sold in China. Additionally, Tesla has their own proprietary system for their vehicles.

Is it software or hardware?

It contains both. A charging standard defines the mating connector that is used for charging as well as the communication protocol used between the vehicle and the charger.

Within which standardization committees was the CCS developed?

The system was developed in the national and international DKE, IEC, ISO and SAE standardization committees with the support of all German and American OEMs.

Which standards are essentially described in the CCS?

The essential elements of the Combined Charging System are:

  • The electrical interface specification for power transmission, which includes safety-related signaling:
    • for AC charging that complies with the international IEC 61851-1 and 61851-22 standards
    • for DC charging that complies with the international IEC 61851-1 and 61851-23 standards
  • AC charging with the Type2-connector (for a 3-phase AC infrastructure as e.g. in Germany in compliance with IEC 62196-2 norm)
  • DC charging with the Combo 2 connector (in Europe) in compliance with the IEC 62196-3 norm
  • For US it is IEC 62196-1 and the Combo 1 connector
  • The communication interface based on ISO/IEC 15118 and DIN SPEC 70121

Main features of the Combined Charging System

The main feature of the Combined Charging System is in line with the principle of “ONE system for ALL”:

  • A combined charging socket in the vehicle (AC or DC can be used, depending on application)
  • One charging control logic for all types of charging methods
  • One charging communication protocol
  • One charging architecture (2 connectors along with the combined charging socket serve all relevant charging scenarios)
  • A wide spectrum of applications with vehicles having voltage ranging from 200 V to 1000 V
  • High charging rates of 350KW+ to enable quick charging of electric vehicles.
  • CCS also uses TLS secure communication which allows for Encryption & Authentication for secured payments, Plug and Charge, commercial use of V2G on the Energy balancing market

The combined charging socket is equipped with all the contacts required for the different types of charging scenarios worldwide. The already introduced Type1 (for USA) and Type2 (for Europe) charging sockets for AC charging (in compliance with IEC 62196-2) will be supplemented with two additional contacts for high power DC charging. A special feature: The Type1 and Type2 connector for AC charging and the Combo1 and Combo2 connector for high power DC charging are both compatible with the compact charging socket.

Protective equipment ensures a safe charging process. A lock in the charging socket prevents the connector from being unintentionally pulled out of the socket during charging. The charging process is managed and controlled by electric control signals and a fully automated digital communication via PLC (Power Line Communication) between the vehicle and the charging station.

Complex charging processes - for example, a charging process that balances power peaks caused by renewable resources - are also possible with PLC.

What benefits can be expected from the use of the Combined Charging System?

From the point of view of the customer, the advantages are obvious: The system is safe, universal and simple.

  • Safe – because the main focus is on the safety functions during the charging process
  • Universal – because of the compact interface that enables the operation of all available charging options
  • Simple – because of easy operation and handling

From a technological point of view, the system is open, robust and future proof:

  • Open – because every company involved can make use of the system and can contribute to its development
  • Robust – because of low maintenance costs
  • Future proof – because the system allows the expansion of new functionalities

CCS Charging Types

CCS charging types – charging duration and performance

The Combined Charging System is the solution to all available types of charging: single-phase or 3-phase charging using alternating current (AC charging from 3.7 kW) as well as DC charging using a house connection up to 20 kW or public charging stations up to 200 kW. The CCS enables full flexibility: Customers can charge their vehicles over a time period of several hours at home (e.g. at night) or can connect them to public fast charging stations. The DC fast charging process enables vehicles to be fully charged within 15 to 20 minutes.

How do the different CCS charging types differ?

  • Fast charging starts with a charging power of 22 kW
  • AC charging is standardized up to 43 kW charging power
  • DC fast charging is presently standardized with a charging power up to 200 kW (350 kW in preparation); today it is mainly realized with a maximum charging power of 50 kW
  • The Mode 2 charging cable makes it possible to charge at any house plug socket
  • Single-phase or 3-phase charging with alternating current (AC charging) up to a max. of 22 kW is called “normal charging”
  • Maximum DC performance in the connector standard is currently limited to 1000V and 200A
  • Higher charging power is possible with special circuits and cooling concepts

CCS Communication

Technical questions "CCS Communication"

What is Power Line Communication (PLC)?

PLC is a communication technology that enables sending data over existing power cables. Basically, over the electric wiring both data signals & electric power are carried simultaneously. The power line is transformed into a data line via the superposition of a low-energy information signal to the power wave. The use of existing cabling greatly reduces cost & maintenance as it avoids the need for putting in extra cabling & plug connections.

Can the st7580 chip be used for implementing the PLC communication?

ST7580 is a narrowband communication device and will not be able to support the required HomePlug Green PHY communication protocol on the pilot line.

What kind of HIGH level PLC use in your Charging System?

PLC chips and boards can be purchased from different members of CharIN. Please feel free to contact the coordination office for further assistance.

Is this communication protocol: CAN bus or RS-485 or something else?

Regarding the chip the communication is based on PLC (power line communication) via HomePlug Green Phy technology. It is not CAN or RS 485. An EV with CAN communication protocols for battery charging will not be able to charge on an EVSE operating with PLC and ISO15118. A physical adapter will also not allow in any way for the EV (CAN Enabled) to communicate with the EVSE (ISO/IEC 15118 enabled).

Is using the CCS MAC address secure enough to use for authorization?

No this not a save way for authorization. For secure communication CCS can use TLS allowing for high level encryption of data.

Is the CCS communication protocol really limiting the maximum charging power to 350 kW at the moment or is it possible to cross that limit?

Yes, it is possible to cross the limit. The limit is not fixed by the protocol but by the actual physical standard. The communication protocol is more flexible. (further definitions are under discussion for the future)

Does CCS support wireless data transmission?

Yes. CCS does support a system where the power transmission is conductive but the communication between the vehicle and the charger is done wirelessly

Is the HomePlug Green Phy (HPGP) module mandatory?

You need to use an HPGP modem or chip. Some chips are now designed and dedicated to automotive application. One is present inside the EV and one is present inside the EVSE.


Technical questions "Infrastructure"

What are the main challenges in the introductory phase of the Combined Charging System?

During the introductory phase of electromobility, one of the greatest challenges is ensuring the provision of a basic charging infrastructure and its connection to authentication and invoicing systems.

The provision of charging infrastructure will stimulate customer demand. This, in turn, will attract the interest of investors. A lack of reliable business models during the introductory phase would hamper the entry of investors into this huge and innovative future market.

The short and medium-term availability of both AC and DC for fast charging to all e-car users, depending on what they need, will therefore be a central theme for a successful market launch. The Combined Charging System, as the universal standard for the AC and DC charging of electric vehicles, will be introduced as the European solution for the standard charging of electric vehicles.

What role does fast charging play in the dissemination of electromobility?

With the availability of a broad network of fast charging infrastructure with multiple charging stations, charging time can be drastically reduced and the driving range considerably extended. This brings us closer to the goal of unlimited, global e-mobility.

Does CCS support pantographs?

Yes. CCS supports pantographs for buses and trucks

With regards to the AC charging with on-board charger what is the power supply possibilities on the vehicle side? Does it support both three phase as well as single phase power supply?

The possible range of power intake is up to 43kW by the car but of course depends on the installed on-board charger and car manufacturer system concept. 1-and 3-phase is also possible with AC on-board chargers.


Technical questions "Interoperability"

Is it an open standard?

Yes. CCS is based on ISO and IEC standards and is open. There are no royalty or patent fees involved in using CCS.

What is meant with CCS harmonization?

To have a common standard it is necessary to convince the manufactures and the decision makers in the countries to use the CCS standard. Different Standards or systems will not promote EV mobility. It is not the aim of CharIN to encourage the manufacturers to use just one CCS connector (type 1 or type2).

What is the CharIN CCS Test System and which companies can help around that topic?

  • Conformance Testing (with CharIN CCS Test System):
  • Testing of every EV and/or EVSE against CharIN CCS Test System, which maps the current status of the development of charging-standards
  • One tool as reference for the standards
  • Cost saving through self-validation of EV and EVSE by manufacturer
  • Possibility of independent testing by third party

Some companies are members of CharIN. They can assist with CharIN CCS Test System for ISO 15118 testing & EV-EVSE communications only. Please feel free to contact the coordination office for further assistance.

The Combined Charging System (CCS) represents the integrated solution for AC and DC charging. It is based on the further development and expansion of the solutions for single phase charging with alternating current to a uniform and integrated system for all types of charging.

Electric vehicles can be charged at charging stations with the Combined Charging System and are “CCS compliant” if they support the following:

  • AC charging with a Type1 connector (e.g. USA) or with a Type2 connector (e.g. Europe) in compliance with IEC 62196-2 or
  • DC charging with connector Combo1 (e.g. USA) or connector Combo2 (e.g. Europe) in compliance with IEC 62196-3. 5.

Is CCS applicable for low voltage vehicles like two wheelers?

CCS is applicable for vehicles with battery pack voltage between 200 V and 1000 V.

Is CCS applicable for high voltage vehicles like buses?

Yes. CCS is supported by many large bus manufacturers globally.

What are differences between CCS Basic, Extended & Advanced?

Different features of charging which are defined by standards. It can be used to distinguish between different products regarding conformance and interoperability. The features are described in the CCS Step Model, which can be shared upon request.

Questions to Claas Bracklo (Chairman of CharIN e.V.)

Interview with Claas Bracklo (Chairman of CharIN e.V.)

In relation to EV adoption across the world, how important is the establishment of the CCS as standard for charging battery-powered EVs of all kinds?

"Due to the unique and future oriented system approach including high power charging and state of the art communication technology, CCS supports the customer adoption of electromobility and secures industry investments into a new technology."

What are the main barriers preventing CCS as standard, and how can they be overcome?

"CCS is already standard in Europe and in the US (and countries following the US standards). Specific national regulations with no explicit benefit for the customer as well as proprietary closed systems are not a danger, but would lead to an intermediate multi system development. The best and most accepted system should be the defacto standard. A standard in just one country or in just one car brand is not a real standard. CharIN is open for discussions to drive one world standard. Tesla is already member of CharIN, we had a first exchange with a CHAdeMO-Representative to figure out the common baseline."

Where in the world CCS will take off first, and how can other countries follow suit to make it global?

"CCS already took off in Europe and in US! All ACEA members are committed concerning the rollout of CCS by 2017, in the US CCS is the only standard! The European directive on charging standards requests CCS as mandatory on public charging infrastructure, the German implementation has taken into effect in March 2016. The next market could be India, with no legacy and the opportunity to decide by price/performance. Korean car manufactures are expected to use CCS at least for the markets in Europe and US."

What approach needs to be taken with the construction of new charging stations - do you think that those involved need to carefully plan out the best locations and technologies for charging, or is it necessary to roll out infrastructure as quick as possible?

"To fulfill the customer’s expectation we do need charging stations working by 100%, easily accessible and connected to the backend for additional support. Quality is the key for customer satisfaction much more than quick availability, to give trust in new technology is a major task. To ensure interoperability of cars and charging infrastructure is one of the main targets of CharIN and the CCS system approach."

What are your expectations for the charging infrastructure over the next 5-10 years?

"We see a broad distribution of CCS as the only worldwide standard. Low volume, non standard priority solutions and standards with a low number of implementing OEMs will just exist in an intermediate timeframe, but will be replaced at least with the next technology step of High Power charging and with the mass production of electric cars based on international standards. National regulations could prevent a 100% coverage, we have to work on a midterm alignment to avoid country depending technologies with additional invests without a customer benefit."

CharIN e.V. - Association topics

Membership rules

What kind of activities can members participate and utilize?

Focus Group F2F meetings, telcos, discussions and publishing of position papers and exchange/discussion about technical descriptions/recommendations and proposals for standardization.

What is Focus Group and how to join?

Focus groups are our topic oriented internal working groups, Charging Infrastructure, Charging Communication, Charging Connection, Grid Integration, Conformance Test & Interoperability. Core members can join all focus groups, but Regulars members can join only one. Please contact the Coordination office for assignment.

Where can I get information on the communication protocol between the vehicle and the EVSE?

The relevant ISO/IEC standards (ISO15118/ DIN Spec 70121) give details about the communication protocol. Additionally, you can get in touch with the CharIN association and we will be happy to share the details.

Where can an OEM get a prototype ECU that implements CCS standard on the vehicle?

Some of our members offer prototype ECUs to implement the CCS standard in vehicles.

Is it mandatory to become a member of CharIN to get details about the standard?

The Standards are available for the public. Only members have access to specific documents and discussions within CharIN which are not for the general public.


Here you will find some abbreviations from the field of electromobility.

  • AC = Alternating current
  • BS = Basic Signaling
  • CCS = Combined Charging System
  • CCTS = CharIN Conformance Test System
  • CP = Control Pilot
  • CPO = Charge Point Operator
  • CT/IOP = Conformance Test/InterOPerability
  • DC = Direct current
  • DIN = German Institute for Standardization
  • Ed = Edition
  • EIM = External Identification Means (External payment)
  • EV = Electric Vehicle
  • EVSE = Electric Vehicle Supply Equipment
  • FG = Focus Group
  • HLC = High Level Communication
  • IC-CPD = In-Cable Control and Protection Device
  • IEC = International Electrotechnical Commission
  • IOP = InterOPerability
  • ISO = International Organization for Standardization
  • ITCC = Interoperability Testing and Certification Committee
  • OEM = Original Equipment Manufacturer, here automotive manufacturers
  • PICS = Protocol Implementation Conformance Statement
  • PE = Protective Earth
  • PHEV = Plug-in Hybrid Electric Vehicle
  • PAC = Peer-Assessment Committee
  • PLC = Power Line Communication
  • PWM = Pulse Width Modulation
  • QAP = Quality Assurance Plan
  • RFID = Radio Frequency Identification
  • SAE = Society of Automotive Engineers
  • SUT = System Under Test
  • UL = Underwriters Laboratories