Got home to find most of my clocks blinking and both computers powered off. Hmmmm... Power failure.

Now, I have TWO UPS - both are APC XS 1500 units, rated at 865w

So, why did my UPS' fail as well? I put on my detective hat, installed PowerChute Personal Edition 1.50 (latest & greatest) and found the following:

UPS1 (older) was powering not only my main system, but the power bar that I hooked the other system & CRT monitor to. As well as a KVM and a set of speakers. Ouch.

UPS2 (newer) was powering only my printer, speakers, switch, cable modem, firewall, and LCD monitor.

Breakdown:

UPS1 : 458 watts, on a battery bought 12/10/02, and would last under 5 min with that load. (barely over half of rated wattage)

UPS2 : 104 watts, on a battery from 6/23/04, and would last 58 minutes.


1st attempt to balance : Moved everything except main system to UPS2.

UPS1 : 285w, 14 min
UPS2 : 329w, 21 min

What the...

Older battery is costing me a lot of uptime.

2nd attempt to balance : Swapped, everything except main on UPS1, main system alone on UPS2.

UPS1 : 268w, 16 min
UPS2 : 285w, 26 min

MUCH better. I'm not sure why the load on my second system changed. I may not have loaded Boinc when I tested before. No biggie, I'll still get around 10 min, and that's plenty for that non-essential computer.

I may move the router/switch/firewall over to the same UPS as the main system. Maybe the LCD screen as well.

Or I might go get an add-on battery pack for it before I do that...