Canadian Chat → UPS making odd sounds

I have an old Belkin F6C900-UNV 900VA/540W UPS.

I replaced the batteries in it last fall (bought them at upsforless.com) and used it for about 4 months on the new batteries, backing up a router at a remote location. 'Round about February I brought the UPS back to my home and left it off and disconnected in a closet in my study - where it's been since.

A couple of days ago I started to hear some faint clicks & buzzes from my closet, and to my surprise they were coming from the UPS!!! Decidedly odd behaviour for a UPS that's been unused/unplugged for 7 months.

I took it outside and plugged it in to an outlet there (in case it was doing to explode) and charged it up. The wiring fault light illuminated (this is a known good wired outlet - GB tester and other UPS'es confirm this), and the UPS still made odd sounds every once in a while (no regular periodicity to it).

Any guesses as to what's going on with this UPS?

1 word, BELKIN

Unplugged it was, but the battery still is connected to some circuitry inside. Some component likely failed and is triggering some kind of relay.

A piece of advice... remove the batteries and trash the UPS. It's not worth it. Trust me I know what a catastrophic UPS failure looks like »Fried UPS, Almost caused house fire

That's what I was thinking.

I've pulled the batteries out.

Every belkin UPS I've owned has failed.

I guess their UPS should be spelled POS.

Aside from replacing their batteries a couple of years ago my APC units have been trouble-free.

shit that was a mess

I have 2 of these Belkin units, and they've operated just fine since 2005. That's a pretty decent run.

I also have some really old (mid 1990's) APC SmartUPS units I need to re-battery.