Power loss detection

Hello

My garage door opener has a problem that when the power goes off, even for just a blip, it needs to be opened the first time afterwards in a certain manner or it looses all the up/down limit location settings. So I need to be able to tell if the 120vac power to my house has gone off, even if it was just a brief flicker, and turned back on and have an indicator beside the opener switch that warns me that it needs to be done this way. I may not have been home when the power went off or may have forgotten by the time I go to open the door (I don't open it daily, maybe once every other week or something)

I don't need to record when or how long or have it email or send a notification or anything, just something basic like a flashing LED

I thought about using a relay with a 120v coil latched on and when the power dropped it would unlatch and run a simple LED flasher on the NC side but it seems that having the coil energized for days/months on end isn't the most effiecient design

I also looked at installing a small UPS for the opener, nothing that would allow it to open if the power went off, just to hold the "memory" but the smallest is still fairly expensive for what it's doing

Any ideas or suggestions are more than welcomed

Thanks

BL