How to Let JK BMS Communicate with The Inverter?

Even though the JK BMS can manage the battery pack well on its own, you may still want it to be able to communicate with the inverter so that you can manage your battery pack more efficiently.

However, one of the challenges of using a JK-BMS is that it uses its private protocol that is not supported by most inverters. This means that you cannot directly connect your JK-BMS to your inverter and exchange data between them. You need a device that can translate the data from your JK BMS to your inverter’s protocol.

In this article, I will introduce you to a project by Uksa007, who has developed a solution that allows you to connect your JK-BMS to your inverter via CAN bus, and also improve your charging logic and efficiency.

Hardware interface for JK BMS communicate with the inverter — Hardware interface for JK BMS communicating with the inverter

Benefits of BMS and Inverter Communication

An inverter needs to communicate with a BMS for several reasons, such as:

To monitor the battery data, such as voltage, current, capacity, temperature, etc. This can help the inverter optimize the power output and efficiency of the solar system.
To protect the battery from damage and ensure its safety. The BMS can send signals to the inverter to stop charging or discharging the battery when it reaches certain thresholds, such as overvoltage, undervoltage, overcurrent, etc.
To improve the charging logic and efficiency of the battery. The BMS can tell the inverter the optimal charging mode and parameters for the battery, such as constant current, constant voltage, absorption time, rebulk voltage, etc.

How to connect JK BMS to inverter via CAN bus?

CAN bus is a communication protocol that allows different devices to exchange data on a single network. CAN bus is widely used in automotive and industrial applications, as it is reliable, fast, and robust.

Some inverters have a CAN bus port that can be used to communicate with other devices, such as BMSs. However, not all inverters support the same CAN bus protocol or data format. Therefore, you need a device that can translate the data from your JK-BMS to your inverter’s CAN bus protocol.

This is where the project by Uksa007 comes in. He has developed a solution that uses an ESP32 device to communicate with a JK-BMS via RS485 or BLE, and then send the battery data to an inverter via CAN bus. He has also designed and built a hardware interface that has all the components needed to connect the ESP32, the JK-BMS, and the inverter.

The project currently supports two types of CAN bus protocols: Pylontech V1.3 and Goodwe V1.5. These protocols are used by some popular inverters, such as Victron Energy Multiplus II GX, Goodwe ES, Growatt SPF, etc.

The project also has a new charging logic that uses constant current and constant voltage modes, with an absorption timer and a rebulk feature. This logic can improve the charging efficiency and lifespan of your batteries.

How to get started with the project?

If you are interested in trying out the project by Uksa007, you will need the following items:

A JK-BMS (any model should work)
An ESP32 device (such as NodeMCU or Wemos D1 Mini)
A hardware interface kit (you can buy it from Uksa007’s Patreon page or website, or build it yourself following his instructions)
An inverter with a CAN bus port that supports Pylontech V1.3 or Goodwe V1.5 protocol
Some wires and connectors

You will also need to download and install the ESPHome software on your computer, and flash the ESP32 device with the firmware provided by Uksa007 on his GitHub page. You will need to edit some configuration files according to your setup and preferences.

You can find more details and instructions on how to set up and use the project on Uksa007’s GitHub page or discussion thread. You can also join his Discord server or Telegram group if you have any questions or feedback.

Conclusion

The project by Uksa007 is an innovative and useful solution that allows you to connect your JK-BMS to your inverter via CAN bus, and also improve your charging logic and efficiency. It is still in development and testing, and it currently supports only one BMS connection per inverter. However, Uksa007 is working on adding support for multiple BMS connections, and he is looking for alpha testers and funding for this feature.

If you have a solar system with a JK-BMS and an inverter, and you want to make them work together and monitor your battery data, you should definitely check out the project by Uksa007. It might be the solution that you are looking for.

Energiepanda can currently deliver JK BMS quickly to customers in North America, Europe, Australia, Asia and South Africa