First of all, I live in Italy, Europe, so keep this in mind for Volt/Watt considerations. Standard voltage in Italian apartments is 220V.
In my living room I have 2 APC ups, one being an ES-550 and the other an ES-700
They each have 4 slots for surge protection only, and 4 slots for surge protection + battery backup.
Just to give all the information, they both got their battery replaced less than one month ago.
The ES-550 works fine, without any problem. On the battery I have connected:
Pc
Monitor
Sony Bravia 46''
4th slot is empty
The ES-700 has the following on battery:
Xbox 360
Ps3 (standby when not used)
Wii (standby when not used)
Netgear 8 port switch (always on)
Here's what happens: the ES-700, randomly, but mostly at night when I'm sleeping, goes like "overload", with the constant beep. If I try to shut it off keeping the power button pressed, nothing happens. The only thing that works is unplugging random stuff (sometimes unplugging 1 console works, other times I have to unplug all 4 devices).
Every time this happens the problem is "real", meaning the 4 devices become unpowered, so it's not just an "alarm no working properly" problem.
While I'm sleeping, of course, the power usage is what described on the list, 2 devices on standy, 1 off and 1 on.
Today it happened again while I was playing with my Ps3. I unplugged it, problem went away. I plugged it again, and it kept working fine.
I just can't figure out what's the problem. The only additional info I can provide is that this behaviour started after a big power outage last december 26 (a blackout that lasted almost all day) but the "surge protection" part of those UPS should be there for those problems, to leverage peaks when power goes away or gets restored.
Another funny thing is, althought it might not be related, for a couple of days after that event the Wii was unable to power on, I thought its power transformer was broken, but then it suddenly started working again. I can be sure it's not the Wii overloading the UPS because the overload happens even if I leave the Wii unplugged.
Any suggestion is really appreciated, and I can provide any additional info, if needed, that didn't come to mind right now.
Thanks.