I remember couple years ago there was talk of GHI developing a power board with a Li-Ion or Li-Po backup so that if the incoming feed went out it would use the battery and then recharge when the power was back, did that ever go anywhere? I could really use one of those.
This community creation module might be what your looking for.
https://www.ghielectronics.com/community/creations/entry/30
It looks cool. I hope to get one.
Thanks DanW, I just emailed the maker to see if I could get some more info. It does look like a possibility.