A few days back woke up to a beeping sound heard throughout the house so I investigated and discovered my garage door opener was not happy and letting us know about it. The opener has a battery backup feature to raise the door in case of a power failure and beeps once a minute if the battery voltage drops below a certain threshold. This replacement AGM 12V battery was only a couple years old and shouldn’t have failed yet so I used the reconditioning mode of my auto charger/maintainer to try and restore it. I ran the program 3 times over two days including a manual deep discharge and so far so good. No beeping and the door raises on backup power.