LiftMaster 8550 8550 Manual - Page 26

Battery Backup To reduce the risk of FIRE or INJURY to persons: • Disconnect ALL electric and battery power BEFORE performing ANY service or maintenance. • Use ONLY LiftMaster part # 485LM for replacement battery. • Do NOT dispose of battery in fire. Battery may explode. Check with local codes for disposal instructions. 1 Install the battery 1.1 Unplug the garage door opener. 1.2 Open the light lens on the right side panel of the garage door opener. Use a Phillips head screwdriver to remove the battery cover on the garage door opener. 1.3 Partially insert the battery into the battery compartment with the terminals facing out. 1.4 Connect red (+) and black (-) wires from the garage door opener to the corresponding terminals on the battery. 1.5 Verify the battery wires are seated in the channel and replace the battery cover. 1.6 Plug in the garage door opener. 1.7 Wait for the green Battery Status LED to start flashing before proceeding to test the battery. ALWAYS wear protective gloves and eye protection when changing the battery or working around the battery compartment. 2 Test the battery 2.1 Unplug the garage door opener. The battery status LED will either glow solid orange indicating opener is operating on battery power or will flash indicating low battery power. NOTE: Make sure the garage door opener is unplugged. 2.2 Open and close the door using the remote control or door control. NOTE: The garage door opener may run slower if the battery is not fully charged. The battery will take 24 hours to fully charge. Channel Battery Status LED 2.3 Plug in the garage door opener. Verify the battery status LED flashing green, indicating the battery is charging. 26