Written 25 Aug 2026. This is a how-to, not a product card.

You don't need a UPS yet

The computer can sit on a house outlet. A blink of the lights is a reboot. Skip a battery box this weekend.

A UPS is a battery box that keeps a computer on through a blink. First-timers hear they must protect the lab, and they buy one before the computer even has Pi-hole. The computer can sit on a house outlet. You don't need a battery box this weekend.

A blink of the lights is a reboot

When the lights blink, the computer reboots. Pi-hole comes back. SSH comes back. That is is the computer still on?. If you were in the middle of keep the computer updated, run the update again. That is annoying. It is not a reason to buy hardware.

When a UPS is later

Come back to a battery box only if the computer already runs overnight backups, and a blink would leave a half-written copy. Even then, a USB disk you can re-run is cheaper than a UPS this month. That is a backup of the house folder. That day is not this weekend.

Skip a lab UPS

Don't buy a lab UPS with extra outlets and a screen. Don't buy a rackmount UPS. Those are closet-later. A house outlet is enough for the computer.

What next

If you are done for the night, shut down the computer without yanking the plug. If you have no second copy of the house folder, a backup of the house folder. Don't buy a NAS. Don't buy a rack. Prefer the BIOS switch before a battery box: turn the old PC back on after a power blip.

Skip

Skip a UPS this weekend. The computer can sit on a house outlet.
An old laptop battery is not a UPS. Confirm the charger: see if the old laptop is actually plugged in.
Skip a lab UPS with extra outlets and a screen.
Skip a rackmount UPS. Those are closet-later.

Sources

Debian: shutdown. Debian: ping. Official pages only. For the computer, see start with what you already have. For the night, see shut down the computer without yanking the plug. For a blink, see is the computer still on?.

Also on this topic

Turn the old PC back on after a power blipLights come back, but the OptiPlex stays off until you press the button. Flip Restore AC / Power On After Power Loss in Setup. Skip a UPS for this. See if the old laptop is actually plugged inBefore you trust the old laptop overnight, confirm it is drawing wall power. A dying battery is not a reason to buy a UPS. Shut down the computer without yanking the plugWhen you're done for the night, shut it down and let it finish writing files before it powers off. Don't yank the cord. Skip this if you only need a reboot after updates. Is the computer still on?You left the computer on. This morning ads are back, or SSH hangs. Check if it is awake before you buy anything. A backup of the house folderA second copy of the house folder, on a USB disk you already have, or on another computer. You don't need a NAS for this. Start with what you already haveDon't buy anything yet. Old laptop first, or a retired OptiPlex from Marketplace.