I want to power a room with a car battery (or more), is it possible?

[Justen]

So I want to power my room with 1 or more car batteries in case of an emergency, my room consists of a 20w light bulb, 4 110w sockets (3 of 4 being used at the time), 2 sockets being connected to a power strip, on the power strip is a desktop server (115w power, planning on for basic internet usage i.e. facebook, web server it self and also to turn on and off as needed to save energy) and monitor (110w, power save mode is scheduled 2.5 mins after no activity), and the other power strip has my laptop (100-240w, I guess assume 110w) and iDevice chargers on it. So now is it possible to power my room with 1 OR more car batteries, if so about how many car batteries would last for a week?

[webjnke1]

In a car ... leaving the dome light on kills the battery by morning. So I doubt you can do any of those things for very long at all.

[adaviel]

You have specified about 575W of load, 47A at 12V, figure 58A with an 80% efficient inverter.
Car batteries (or rather, deep-discharge RV batteries which is what you want) run about 120Ah.
So you'd need about 80 batteries to last a week. Or rather fewer but bigger golf-cart batteries.
Or a generator to charge the batteries.

If you just run your laptop a bit (my PS says 65W), and use 12V LED lights, you can do rather better - about a day on one battery, and recharge the battery by running your car engine. You can get 12V laptop power supplies, which are more efficient than using an inverter and then a 110V PS.
Much the same problem I face on my sailboat, if I don't have a big solar panel and don't run the engine.

[Drunkentoothbrush319]

As you turn on all those devices, one car battery power can support less than 2 hours ( need a 1000W DC to 120V AC converter ). It needs 84 piece car batteries to support 24/7 non stop .

[Gene]

Mom and Dad flip the breaker on the room to get you unplugged from all that?

[Alok T]

The other people responded have given calculations. In my suggestion the best option is use LED bulbs for lighting purposes and use mobiles for accessing internet.

[LG]

I think you're sometimes getting volts confused with watts. The 20W light bulb sounds right. But laptops don't use 240W. More like 20-30W. But the power supplies are usually switchers and are rated for 100-240V so they can be used in Europe or US.
But if I were to take a stab, all that stuff in your room probably takes something like 200W. A typical car battery nowadays is like 60 amp-hours, meaning the battery can supply 60amps for one hour, or any combination of amps and hours where amps times hours equals 60. At 12V, this works out to 60x12 or 720 Watt-hours. So at 200W one car battery would last for 3.6 hours. And then just multiply that by the number of batteries and that's how long it would last, assuming continuous use. You would also need an inverter to convert the 12VDC from the battery to 120VAC.
Car batteries wouldn't be the best choice for this as they don't do well in deep discharge situations. Just a few complete discharges can kill them. Marine batteries or gell-cells would be a better choice.