Maintenance
Replacing the Backup Battery in a FANUC Controller
For maintenance technicians performing routine preventive replacement of the controller memory backup battery before it fails and causes program or data loss.
- Step 1.
Check the battery alarm history
Review the alarm log for the low-voltage battery alarm (system-035) to confirm replacement is due, and note how long ago it appeared.
- Step 2.
Power the controller on briefly, then off
Turn the controller on for about 30 seconds so memory contents are refreshed, then turn the controller off. The following steps run with power off.
Caution: Do not leave the controller powered on throughout the swap. Follow the documented power-off sequence.
- Step 3.
Apply lockout/tagout before opening the cabinet
With power off at the disconnect, apply LOTO before opening the controller cabinet to access the battery unit on the backplane or main board.
- Step 4.
Remove the old battery unit
Disconnect the battery connector and remove the old battery unit from its holder.
- Step 5.
Install the new battery unit
Fit the new battery unit into the holder and reconnect the connector securely. Complete removal and install within 30 minutes of powering off so memory contents are retained.
- Step 6.
Close the cabinet and restore power
Refit the cover, remove LOTO, and restore power to the controller.
- Step 7.
Verify data integrity and clear the alarm
Power up the controller and confirm all programs and positions are still present. Clear the low-voltage battery alarm from the fault log.
Common questions
- How long does Replacing the Backup Battery in a FANUC Controller take?
- Replacing the Backup Battery in a FANUC Controller is rated Basic and takes about 20 minutes across 7 steps.
- What tools do I need?
- You will need Replacement lithium battery unit (correct FANUC part number), Screwdriver.
- What should I do before starting?
- Correct replacement battery part number confirmed for the controller model. Time budget to complete the swap within 30 minutes of powering off.
- What is the first step?
- Check the battery alarm history. Review the alarm log for the low-voltage battery alarm (system-035) to confirm replacement is due, and note how long ago it appeared.