AC300 Error code 004 and 015

Need help… I have an AC300 and 4 x B300. I have been running this unit for nearly 1 year with no problems. Once 100% charge has happened the unit alarms 004, 015 errors and shuts down which turns the power off to my home. I have depleted all batteries, so recalibrated them hoping it would fix the problem. Nope, no luck. I have connected the unit to Bluetooth to check for updates, none. I have performed 1 update via Bluetooth in April this year. No more updates available. Any help would be much appreciated.

@shellycat19 Please check the below information:

  1. Check whether the firmware is the latest and perform a complete battery self-learning
  2. If it is AC charging, try setting the UPS mode to PV priority mode and set the default value to 95%
  3. If it is PV charging, the DC charging cable has two sets of MC4. Please connect the solar panel to only one set of MC4. Test both sets separately to see if 004 will be reported. If only one channel will report an error, there is a problem with that PV channel. , if both PVs will report errors, please let me know.

Problem has been rectified. Nothing major, thank goodness. Had a solar electrician have a look and it was one of the MC4 connectors.
The unit is absolutely fantastic and has performed brilliantly over the last year. I would love to swap the AC300 out for the AC500 one day in the future, the specs on the AC500 is all I would ever need or want.

@shellycat19 Thanks for your update.