FLA48200/FLA48300/FLA48500 and LUX-Y low-voltage LiFePO4 batteries (BMS fault code list)
Felicity C02 error code
Battery under-voltage: total pack voltage dropped below the BMS lower protection limit.
Likely causes
- Deep discharge after a long outage
- Load left connected after the low-voltage cutoff
- Low-voltage cutoff set too low
- Weak or imbalanced pack
Checks to run, in order
- 1Read the pack voltage on the battery display or app
- 2Check whether the load was left on after shutdown
- 3Compare the inverter cutoff setting with the battery datasheet
- 4Recharge and see whether the pack recovers
Fixes
- Charge the battery immediately from PV or grid
- Disconnect non-essential loads until the pack recovers
- Correct the low-voltage cutoff setting
- Restart the unit; if the error persists, contact the repair centre
When to escalate
If the pack will not recover above the cutoff after charging, or one cell stays low, escalate for battery service.
Fix it with the right tools
Check the system around the fault before replacing parts: load, battery bank, PV string and commissioning settings. If you need a second opinion, send the code and your inverter model to our team.
Before you open the inverter
- Isolate both the AC and DC sides, then confirm the display is dead before touching terminals.
- Use insulated tools and one hand where possible. DC arcs do not self-extinguish like AC.
- If you see burnt terminals, swollen cells, leaking electrolyte or a burning smell, stop and escalate instead of resetting the fault.
Questions installers ask
What does Felicity C02 mean?
Battery under-voltage: total pack voltage dropped below the BMS lower protection limit.
How do I fix Felicity C02?
Charge the battery immediately from PV or grid Disconnect non-essential loads until the pack recovers Correct the low-voltage cutoff setting Restart the unit; if the error persists, contact the repair centre
When should I escalate Felicity C02?
If the pack will not recover above the cutoff after charging, or one cell stays low, escalate for battery service.
Can I reset Felicity C02 myself?
Only after isolating the AC and DC sides and running the checks above. If Felicity C02 returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show Felicity C02?
Felicity C02 is documented for FLA48200/FLA48300/FLA48500 and LUX-Y low-voltage LiFePO4 batteries (BMS fault code list). Confirm the code on your own unit's display or manual before ordering parts.
More Felicity error codes
- Felicity 04Low cell voltage / over-discharge protection.
- Felicity 05PV over-current fault: the PV input current exceeded the inverter's PV input limit.
- Felicity 18PV short-circuit fault on the PV input; in the warning list the same number means battery under-voltage alarm.
- Felicity 19Battery open-circuit alarm: the inverter no longer detects a battery on its terminals.
- Felicity 20Battery SOC low alarm: the battery's state of charge has fallen to the low-SOC warning threshold.
- Felicity 21BMS communication alarm: abnormal communication between battery and inverter in non-SOC mode.
Guidance reviewed 17 October 2026 by the Mishka Energy installer team. Error codes vary by brand, model family and firmware; confirm against the manufacturer manual.
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