!!
critical Upgraded
Error Code Battery symbol is not flashing and unit frozen (not responding)
Unit microcontroller halted from a steep battery voltage drop.
? What Causes This
Prolonged low voltage to controller input or direct load bypassing the regulation mode.
✓ How to Fix It
Remove all external loads, charge the battery externally (or by connecting another regulated source) and restart the unit after resetting battery terminal 3 briefly. Let system adjust for safety before reactivating fully.
Source: page 24 of the official manual
From the manual
This error code appears in:
Upgraded 30A Solar Charge Controller