A product I wished existed: A small DC UPS

Basically build the guts of a USB-C mobile battery and give it some more trickle charging and input switching smarts so I can use it to replace the power brick for my router, an IP camera or anything that runs off a 5V/7.5V/12V DC barrel jack and makes it stay up over short (<1hr) power outages.

All the UPSes out there are stone-age lead-acid battery things or big heavy expensive 120V AC Jackery-type devices