After the update release today I started working on using my Growatt with canbus and diybms. After hours of experimentation I got it working. The problem was knowing what pins on the growatt BMS connector coincided with the canbus pins. The manual shows Can-H and Can-L but does not tell you what ground is. I ended up removing the Canbus/RS485 card and probing around until I found it.
Steps:
Enable Pylontech in Charge/Discharge configuration on diybms web interface.
Make a cable. You’ll want to make Pin4 is CAN-H Pin 5is Can-L and Pin 2 Ground. For me I used an already made up cable and just cut off one end. Blue/White was Can-L, Blue was Can-H and Orange was Gnd. My biggest problem was simply finding which pin ground actually was on for the inverter.
Enable BMS communication in Growatt with Menu option 5 set to Li. This will enable, and immediately take you to Menu Option 36. Set this to Protocol 52.
You should now have communications with controller. Set the settings to desired settings after watching Stuarts release video and have fun with more integration!
Well this post isn’t about the current shunt. But I found some at Quest Components and bought the last 10 they had so they are currently out of stock. I had a heck of a time soldering them without bridging so I’m down to 3 but 2 working current monitors now.
I tested some stuff but growatt seems not to send any data via the can bus. I did measure ground - CAN H and ground/CAN L and both have voltage 2.25. This seems not correct. Can you measure your voltage and share the information ? Thanks !