Tarik is Right it is about power consumption for sizing, and batteries for up time. in your case:
- LCD 48: Peak 300 Watt
- PS3 Slim: Peak 110 Watt
- Stereo System: Peak 325 Watt
so in total you would have 735 Watt of Peak Consumption, converting to VA with 0.85 efficiency, you would need a 864 VA system. so a device like the one i have (1000VA) installed would do. please note to protect electronic systems it is
highly recommended to use an Online UPS, because the switch over with an offline (backup) UPS can damage your system, i know because i had a $100 backup UPS from APC protecting my TV and when the power went, it screwed up my TV, thank god it was still under warranty and i got it fixed.
Like i said, it is investment protection and here is the math:
- LCD for :$1200
- PS3 for :$560
- Cable Vision HD Decoder for :$140
- Apple TV for :$150
- DSL modem for :$90
- Cannon Printer all in one for :$240
so i spend and extra $600 to protect $2380 and any data stored on them thus my protection plan was 25% of initial my investment. i could have gotten a smaller Online UPS for a smaller budget but i had power growth to take into consideration.
APC Backup UPS site:
http://www.apc.com/products/family/index.cfm?id=27
APC Online UPS site:
http://www.apc.com/products/family/index.cfm?id=163
you can use this site to compute your run time and number of extended batteries required. make sure the UPS is at-least
20% larger than you need in terms of VA.