OpenDTU-OnBattery is a fork of OpenDTU, which adds support for battery chargers, battery management systems (BMS), and power meters on a single ESP32. Its Dynamic Power Limiter can adjust the inverter's power production to the actual houshold consumption. In this way, it is possible to implement a zero export policy.
See the documentation to learn what hardware to acquire, how to initialize it with OpenDTU-OnBattery firmware, and how to configure OpenDTU-OnBattery for your hardware.
Generally speaking, OpenDTU-OnBattery and the upstream project are compatible with each other, because OpenDTU-OnBattery mostly only extends the upstream project. However, there are a few notable differences aside from the added functionality:
- OpenDTU-OnBattery, due to its code footprint, cannot offer support for over-the-air (OTA) updates on ESP32 with only 4MB of flash memory. Consult the documentation to learn more.
- Unlike in the upstream project, you must compile the web application yourself when attempting to build your own firmware blob. See the documentation for details.
The canonical documentation of OpenDTU-OnBattery is hosted at https://opendtu-onbattery.net.
You may find additional helpful information in the project's community-maintained Github Wiki.
To find out what's new or improved have a look at the releases.
OpenDTU-OnBattery is actively maintained. Please note that OpenDTU-OnBattery may change significantly during its development. Bug reports, comments, feature requests and pull requests are welcome!
The original OpenDTU project was started from a discussion on Mikrocontroller.net. The original ambition was to replace the original Hoymiles DTU (Telemetry Gateway) to avoid using Hoymile's cloud. With a lot of reverse engineering, the Hoymiles protocol was decrypted and analyzed.
In the summer of 2022 @helgeerbe bought a Victron MPPT charge controller, and didn't like the idea to set up a separate ESP32 to receive the charger's data. He decided to fork OpenDTU and extend it with battery charger support and a Dynamic Power Limiter.
In early October 2024, the project moved to the newly founded GitHub
organisation hoylabs and is since maintained by multiple community members.
- Special thanks to Thomas Basler (@tbnobody), the author of the upstream project, for his continued effort!
- Thanks to @helgeerbe for starting
OpenDTU-OnBattery, for his dedication to the project, as well as for his
trust in the current maintainers of the project, which act as part of the
hoylabsGitHub organisation. - We like to thank all contributors. With your ideas and enhancements, you have made OpenDTU-OnBattery much more than @helgeerbe originally had in mind.