Load check
Tell it what is going on the battery side and it works out the watts, adds a quarter for whatever gets plugged in next, and leaves only the units rated to carry that.
Nothing is on the list yet. Add a count beside the gear standing on your bench and the tally fills in below.
Why it adds a quarter
A battery backup loaded to its ceiling has nothing left, and the first thing anyone does after installing one is plug in something else. Sizing at 125 percent of what you counted leaves that room, and it keeps the unit off the part of its curve where runtime falls away fastest.
What not to put on the battery
Anything with a heating element belongs on the surge-only outlets: laser printers, space heaters, kettles. They draw far more than their labels suggest at switch-on, and a battery sized for a desk will drop the whole load trying to hold one up. Motors are the same story for the same reason.
Runtime is a separate question from whether a unit carries the load at all. Both matter, but only the second one is arithmetic: minutes depend on how full the unit is, and the fuller it is the fewer of them you get.
What the range covers
20 battery backups with a published watt rating, from 210 watts on a desk up to 9000 watts in a rack chassis.
See all of them