I'm looking for something.

[Gooseberrysoda]

I'm planning on doing a really cheap "Mod" that mostly involves duct tape. But I need to know it there's something that's like an electrical output/socket that runs of batteries and has a decent battery lifetime. I don't know if such a thing exists, but if it does, tell me PLEASE.

[Reverend]

What exactly are you trying to do?

[MasonB15]

You could probably make something like that...

What exactly are you trying to do?

[REPO Man]

If he wants to make an electrical outlet that uses battery power, he's SOL, AFAIK.

[noiseredux]

I've thought about this in the past as well. I dnt think it's possible, though.

[Gooseberrysoda]

I want to plug a small TV and a console into an outlet to make something that could almost be considered portable.

[PharmaceuticalCowboy]

Computer battery backup could work, kinda expensive though.

[HoboJoe]

I call them portabll generaters.....they usually have outlets right on them....noisy though...and not super portable <.<

[MrPopo]

I want to plug a small TV and a console into an outlet to make something that could almost be considered portable.

If you're looking for actual portability then you have to mode the console and TV screen. The wall outputs 120V AC, while most console/screen combinations after modding will run off of 9V DC. There is no real portable way to generate 120V AC without a generator, which isn't really all that portable.

[Anapan]

There's the "Black & Decker Pocket Power" - 3/4"x6"x3 1/2". It weight almost nothing and provides USB and 2-prong inverted power (both can run simultaneously if they don't exceed 16 watt). I can pick them up for $20 at the local XS-Cargo store. It's inverter outputs 115V at 16Watt - not enough to power a regular tube TV (it would just beep then shut off), but it should be able to power a console for a while. Add on a portable DVD player, or DC or battery powered handheld TV that accepts RCA input and you're set - I've powered my handheld TV with it's USB power.
The biggest problem is the battery/inverter. In order to get some real playtime out of it you'd need one of those vehicle battery boosters with the built-in inverter - the ones that are the size, weight and shape of a car battery. I've successfully gotten one of those powering a PS2 and a 12" portable DVD screen to last through an 8 hour road-trip.
A common brand is the Eliminator Booster Pack - they come in several sizes, so one of those may come in an acceptable size for your project.

Edit:
The only other thing I've heard about these DC-AC inverters is that they almost never output a true sine-wave AC signal, I've noticed that the adapters for my different machines make a lot more noise while charging or powering my electronics, and most of them have warnings in their manuals about powering them with "modified sine wave" power. If you're powering an expensive machine with it, you may want to look into this some more.