DC voltage too low for backup power
Fronius · Primo GEN24
What does 902 mean?
The DC voltage from the battery is too low to initiate or sustain backup power operation with the Fronius Primo GEN24 208-240 inverter. This indicates the battery is either critically discharged or faulty.
Common Causes
- DC voltage too low for backup power.
- Battery deeply discharged.
- Battery fault.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Check the battery's state of charge (SoC) and voltage; ensure it's above the minimum threshold required for backup power. The battery may need charging from the grid (if available) or PV.
- 2
Measure the battery voltage at the Fronius Primo GEN24 208-240 inverter's DC terminals to confirm it aligns with the battery's internal readings and is sufficient for backup operation.
- 3
Inspect DC cables and connections between the battery and inverter for any issues causing voltage drops.
- 4
Refer to the battery manufacturer's manual for specific low-voltage recovery procedures or diagnostics if the battery is faulty or deeply discharged.
- 5
Confirm that the battery parameters in the inverter settings are correctly configured for the connected battery model.