ESPHome-based replacement/emulation controller for an EVBox G2 charge point using an M5Stack AtomS3 Lite and ATOMIC RS485 Base.
- EVBox G2 CP/modem emulation
- Remote start via command 31
- Delayed G2 start via 6A state 07 → command 6B
- Remote stop via command 32
- Home Assistant controls
- Solar surplus feedback control using grid power
- Session tracking:
- session id
- start time
- end time
- duration
- energy
- estimated solar surplus share
The controller uses a single EVBox Charging Mode selector as the main start-control mechanism.
| Mode | Authorization | Start behavior | Dynamic current control |
|---|---|---|---|
| Off | Denied | No start allowed | No |
| Manual | Allowed | Only starts after pressing the Home Assistant EVBox Start Charging button |
No |
| Auto | Allowed | Starts automatically after RFID/card authorization | No |
| Solar Surplus | Allowed | Starts automatically after RFID/card authorization | Yes |
In Manual mode, RFID/card authorization is accepted, but the controller will not automatically send the EVBox start/current-limit command.
A charging session is only started when the EVBox Start Charging button is pressed in Home Assistant.
In Auto mode, the controller accepts RFID/card authorization and automatically continues the proven EVBox G2 start flow:
RFID/card authorization
→ command 22 accepted
→ command 6A state 07
→ delayed command 6B
→ command 23 metering started
→ command 26 state 17
- M5Stack AtomS3 Lite
- ATOMIC RS485 Base
- EVBox G2 charge point
This project provides RS485 CP/modem emulation for selected EVBox G2-like charge points, with remote start/stop, dynamic current limiting, solar-surplus charging and charging-session tracking.
Experimental project. Not affiliated with or endorsed by EVBox.
This project interacts with EV charging hardware and RS485 control signals. Use at your own risk. Incorrect wiring or configuration may damage equipment or create unsafe charging behavior.
This project is experimental. It is not an officially supported EVBox integration.
Do not use this unless you understand EV charging safety, electrical installation limits, circuit protection, phase configuration, and local regulations.
The current limit sent by this controller must never exceed what your installation, cable, breaker, EVSE and vehicle can safely support.
This project interacts with EV charging hardware and RS485 control signals.
Use at your own risk. Incorrect wiring, configuration or current limits may damage equipment or create unsafe charging behavior. Never configure current limits above what your installation, breaker, cable, EVSE and vehicle can safely support.
This project builds on the work and published research of others in the EVBox and smart-charging community.
Special thanks to:
- Maarten Tromp for his extensive EVBox protocol documentation and reverse-engineering work on the internal EVBox Max communication protocol. His documentation was an important reference for understanding the RS-485 protocol, frame structure, addressing and command behavior.
- Harm Otten for his work and write-up on smart charging at home, including practical concepts around using EV charging in a home energy-management context.
Their work helped make this project possible.
References:
- Maarten Tromp — EVBox protocol documentation: https://www.geekabit.nl/projects/managed-ev-charger-to-stand-alone/protocol/
- Harm Otten — Smart charging at home, and more: https://olino.org/blog/us/articles/2019/07/17/smart-charging-at-home-and-more/