I've got a nice functional small Uninterrupted Power Supply, which has been serving nicely so far.

Had a power outage last night, late, and the high pitched whistle woke me so I was able to get to the computer and do a proper shutdown.

But, the UPS has three outlet plugs - one for the computer, and I've connected a simple power bar to another because I've got more than three things I'd like to connect - modem, external drive, printer, ethernet splitter.

But, while I was able to properly shut down the computer, the other things that were connected through the power bar simply got cut off. Seems to mean that the UPS worked on only the one outlet, but not another.

Ideas?

Take a good look at the back of your UPS.

Many models have a few plugs running of the internal battery after a power cut, but will also have a few plugs which are filtered for electricity spikes, but which will not run when the electricity goes down.

Mostly used for example for your laser printer. Basic level of protection, and the printer is not really needed during a power cut...

Further check if your UPS has a data cable to connect to your PC via USB.

You can then easily configure an automatic shutdown of your PC when the battery of the UPS runs low (on a longer outage). (Windows: Control Panel / Power Options)

welo