Hi,
Did you use the CAN or RS485 communication ports? Check your User Manual, then try a standard RJ45 cable on the RS485 ports.
If the PIN's on the inverter and battery do not match, you may need to crimp a customised communication cable.
The next step would be to try out the Battery Brands on the inverter: try Standard or Polyntech maybe
I bought an NEnergy 3.8KW 48V 80A battery, the pin layouts on the RS485 port seems to match the RS485 pin layout on the Luxpower Eco Hybrid SNA 5000 inverter:
PIN 1: RS485 B
Pin 2: RS485 A
I am still waiting for an installer to get the Certificate of Compliance. Hopefully the communication will work outright!