MUST be connected to the opener, while setting limits, for C. Page 2: Battery Replacement GREEN, YELLOW and Battery Back-Up port. There are all kinds of reasons why your garage door won’t open, but many of them very simple to fix. If your garage door opener operates via remote control, you can remove the old batteries by simply sliding the door located at the back of the remote control. Battery Back-Up will NOT turn on until the opener has COLOR INDICATION ACTION REQUIRED power. A 12 volt battery, minimum of 12AH. a 750-1000 mA DC power unit. Test the battery yearly according to the instructions in your owner's manual. Located in the motor unit, the battery supplies power to the opener if the power goes out. Use the CHART. YELLOW GREEN RED E . RED. A transfer relay. AC power damage the Battery Back-Up Unit. To remove the old batteries, open the battery chamber and lift the old cells. This DIY repair guide explains how to replace the back-up battery in a garage door opener. Few pieces of wire, and a power outlet. Now that you know how to replace battery in overhead garage door opener, you can effectively replace the batteries and get your garage door opener back up and running. Firstly you’ll want to check your batteries. A 600 watt inverter. Most types of door openers have battery compartments located at the bottom part of the control box. D. Restore power to the garage door opener. Plus the backup power to the nearest AC outlet and plus the garage door opener to the backup power unit. You can put all these in a small 12x12x4 box and hang it near the existing garage door opener.