Gliderol opener shows E12; battery backup (if fitted) does not operate the door during mains failure, or beeps indicating battery fault.

Safety first: Turn off mains power before working on the battery. Observe polarity to avoid short circuits.

Steps to restore battery backup:

• 1. Locate battery pack: Many Gliderol units have an internal 12V sealed lead-acid or Li‑ion pack. Remove the cover to access it.
• 2. Inspect connections: Ensure the battery harness plug is fully seated on the control board and the spade terminals on the battery are tight and corrosion‑free.
• 3. Test battery voltage: Use a multimeter to measure battery voltage. If it is significantly below the rated voltage (e.g., under 11V for a 12V SLA), replace the battery with the same type and capacity.
• 4. Charge cycle: Restore mains power and allow the opener to charge the new battery for several hours, then test operation with mains power disconnected.

If a new, correctly rated battery still triggers E12, the onboard charger or battery sensing circuit on the Gliderol control board is likely faulty and the board may need replacement.