EVCC and V2G Software Stack: ISO 15118-2 / ISO 15118-20 Technical Guide
EVCC is the vehicle-side charging communication controller. The V2G software stack handles ISO 15118, DIN 70121, EXI, SDP, TLS, and Plug & Charge communication details.
Quick Facts
Summary
An Electric Vehicle Communication Controller (EVCC) is the vehicle-side controller that establishes communication with charging equipment, exchanges capability information, negotiates charging parameters, and monitors charging states.
A V2G software stack implements DIN 70121, ISO 15118-2, ISO 15118-20, EXI encoding, SDP discovery, TLS security, and Plug & Charge certificate flows.
EVCC Hardware and V2G Software Responsibilities
| Layer | Main Responsibility |
|---|---|
| EVCC hardware | CP / PP sensing, PLC interface, CAN, relay or lock control, power management |
| V2G communication | SDP, TCP/TLS, EXI, V2G messages, and charging state machine |
| Vehicle integration | Exchange charging needs with BMS, VCU, OBC, and thermal systems |
| Security | Certificate validation, TLS connection, Plug & Charge, and error handling |
ISO 15118-2 and ISO 15118-20
ISO 15118-2 is common in CCS charging programs and supports AC / DC charging, contract certificates, and Plug & Charge. ISO 15118-20 expands the communication model for advanced charging use cases, including bidirectional charging and enhanced service capabilities.
Key Communication Elements
| Element | Description |
|---|---|
| PLC | HomePlug Green PHY communication over the control pilot line |
| SDP | Discovery of TCP or TLS V2G services from the charger |
| EXI | Efficient binary representation of XML-based V2G messages |
| TLS | Encrypted channel for certificate-based secure communication |
| PnC | Plug & Charge authorization using contract certificates |
FAQ
Is EVCC the charger?
No. EVCC is the vehicle-side communication controller. OBC or DC charging power modules handle energy conversion.
Is TLS always required?
TLS is important for Plug & Charge and secure communication. The exact requirement depends on protocol version, charging mode, and OEM specification.
Which ECUs does EVCC usually communicate with?
Common interfaces include BMS, VCU, OBC, DCDC, thermal controller, cluster, and vehicle gateway.
Technical sources and scope
These primary sources cover standards, components and communication principles. KopherBit features, ratings and deliverables remain company specifications subject to the selected model, revision and project validation. Citing a standard does not establish product certification.
- ISO 15118-2:2014
First-generation network/application protocol scope, not product interoperability or certificate test results.
- ISO 15118-20:2022
Second-generation communication and bidirectional transfer; check the 2026 amendment and the project baseline separately.
Sources checked: 2026-10-03
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