BAT_Comm-FAIL Alarm

This alarm means one of two things: 

1. There is no communication between the inverter and the battery

2. The wrong battery has been selected (this includes no battery)

Troubleshooting a potential communication issue:

  • Check the CAN or RS485 wire between the battery and the inverter. Inspect both ends and make sure that the wires spring clamp terminals have a good bite on them. Pull the wires out and ensure there is plenty of bare conductor exposed. Make sure the wires all landed in the proper terminals
  • Double check that the battery is powered on. If the battery is off, there won't be any communication between the two devices.
  • Be sure that the communication wire is not in the same conduit as the high voltage DC lines - noise will cause issues 

Verifying that the right battery has been selected:

  • While at the main screen, press Enter and then Up once to highlight Advanced Settings
  • Press Enter and then Down until "Battery Control" has been highlighted, then press Enter
  • With "Battery Select" highlighted press Enter
  • The first battery that is shown is what the inverter has currently selected
  • Lg_HV is the LG RESU10 battery pack
  • B-BOX HV is the BYD B-Box HV battery pack [note: this battery must be commissioned FIRST]
  • With the correct battery selected, press Enter and then Enter two more times to save the Force Charge and Over Discharge rates
  • If there is no battery connected to the inverter, then No Battery must be selected or else the alarm will persist

Victor is the author of this solution article.

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