Actually none of these quite compare to a telephone central office, where the battery bank is absolutely huge, and all the essential stuff runs off the batteries which are constantly kept charged. A properly equipped telephone CO can run for two days on just the battery.
When I was a kid, growing up in a rural area with a telephone engineer for a father, we had a similar battery bank in our basement, it took up an entire room. The lead acid batteries had to be routined and their specific gravity and charge levels checked on a weekly basis, which I learned to do when I was about eight. You should have seen me in the rubber apron and gloves, not to mention the safety goggles.
Ours was NOT a true UPS, though, because it used an armstrong switching method - when the power went off, someone went down to the basement and threw the big switch, with a small baseball bat size handle, and the lights came back on. Ours would be the only house lit up for miles around, and we got lots of visitors on cold winter nights.
Real gun control, carrying 24/7/365