I use a usp battery backup, the lights and extraction fan are hookup up to it so if I lose power it’ll kick over to the battery.
Battery backup wasn’t designed to run 700w of draw, so I extended out the battery wires and rigged it to an Abrams tank battery (thank u army base for not knowing how to maintain batteries)
U can usually dig up a perfectly good usp from a best buy dumpster or another electronic box store dumpster. Battery goes bad so people just toss them not knowing they can be replaced. I also pull hard drives for magnets and DVD burners or laser projectors for the laser diodes.
Then again - I’m on a first name basis with the store security guys, mostly cuz they tell me to get the hell out of there dumpsters. Hey, if they don’t want peeps in them they should lock them up.