37
RI Charge Error
Fronius · Perfect Charging
What does 37 mean?
An error occurred during the RI (Internal Resistance) charging process. This specialized charging method monitors battery internal resistance, and a fault indicates a significant deviation from expected behavior or a measurement issue with this diagnostic cycle.
Common Causes
- A significant and unexpected change or instability in the battery's internal resistance during the RI charge measurement.
- Malfunction in the charger's dedicated RI measurement circuit or its associated sensors.
- The battery condition is not suitable for RI charging, or the battery itself is severely degraded.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Assess the battery's internal resistance independently using a dedicated battery diagnostic tool to confirm its health.
- 2
Consult the charger's specific manual for troubleshooting steps related to RI charging diagnostics.
- 3
Verify the charger's RI charging parameters and settings to ensure they are appropriate for the connected battery type.
Verified technical data. Last updated: March 2026
Related Faults
Source: Fronius Perfect Charging