> Agreed. I have a small home server setup that draws 40W idle and I toyed with the idea of replacing the UPS with a small 1-2kW battery inverter plugged into t

> Agreed. I have a small home server setup that draws 40W idle and I toyed with the idea of replacing the UPS with a small 1-2kW battery inverter plugged into the wall. No idea if this would work in practice, but you might be able to backfeed your battery with a regulated 11.9V onto the 12V lines and backfeed at 4.9V on the 5V lines, so when the power supply shuts off and puts 0V on the 5V and 12V lines, the battery will start back feeding, but when the grids power supply puts out 5V and 12V, no current will move. (Will need blocking diodes to avoid back-feeding the battery that’s kept topped off by its mains charger) Saves you some DC->AC->DC conversions. You might need a 3.3V leg as well. And maybe negative voltages if those are used for anything anymore?