Atlas Copco controller shows E009 Battery Voltage High
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: High charging voltage can cause batteries to vent explosive gas. Ensure good ventilation and avoid sparks or open flames near the battery bank.
- Measure DC voltage: With a multimeter, check battery voltage while the charger is operating. Compare to the charger specification (typically 13.6–14.4 V for 12 V systems).
- Inspect charger settings: Some Atlas Copco chargers have selectable voltage or battery type. Confirm the setting matches your system (12/24 V, lead‑acid type).
- Check charger output: If voltage is significantly above spec, disconnect the charger output and re‑measure. Persistent overvoltage indicates a failed regulator; replace the charger.
- Verify battery wiring: Ensure batteries are wired correctly in series/parallel as per the generator manual. Incorrect wiring can present the wrong voltage to the charger.
Do not operate the generator long‑term with an overcharging condition. Replace the charger or have it serviced.
Repair Difficulty
Required Part
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