Question Wattage of UPS


Jul 15, 2015
Looking to get a battery backup UPS, to keep my PC running long enough to safely shut it down in case of an outage. I know my PSU is 850watts, but the machine definitely does not run at that wattage. I used Joulemeter and it reads that i'm using about 130 watts, though it seems to be estimating my monitor's wattage.

There seems to be a good deal on 550VA UPS that can handle 330 Watts, but is this enough to power my PC, one monitor, and a DROBO with 4 disks in it? Obviously other perriferials don't need to be on the battery (printer, speakers, ect), just the valuable parts.


My recommendation is to go online and apply 2 or 3 manufacturer based calculators.

For example:

Do two things: First over estimate what you think you need x 2 (130 x 2 = 260) and then look at the product's claim and divide by 2 (550/2 = 275).

If the UPS result is greater than what you need/require then that UPS should meet your requirements.

Caveat being your sense of how long it may take you to actually get back to your PC and shut it down while the PC is actually /only being provided with UPS power.

If you are in the habit of backing up/saving any on-going work before leaving your PC then a power loss is much less of a threat.

Even if the UPSs' time limit is exceeded.