Ejector Pit & Sump Pit Combined - Whats a good backup option?
Computer UPSes are super cheap these days.  See if you can find one rated for the watts that your system needs with a good margin.  They are readily available up to 1500 less than $500, and they'd just plug in in line inbetween the equipment and an outlet.  Most of them self test every day and alarm on failure of the battery or of mains power failure so you'd know if the breaker flipped.  Make sure the one you buy doesn't do a self-shutdown when its running on battery and can't detect a load.  That used to be more common.