Alright I have a 200 Watt Power Inverter that I just bought from Walmart last Sunday. I have it in the trunk of my car running my Xbox, and my LCD monitor in muy Sun Visor. But I am running the Pos. & Neg. to an extra Battery I have in the trunk. The thing I have trouble with is that the battery is Dry-Cell, so I constanly lose power after 1 use of gaming. So I was wondering how could I run it to the main Battery under the hood of my car?  

There are kits that extend the battery cables to the engine bay if the battery you're using is not connected to the alternator for the charge. First off the alternator needs to be rewound to handle the higher demand of energy required to keep the charge of the new load (battery). Or get a new 130amp or a 150amp digitally regulated alternator. And if you play the games on the monitor that you use for the system, that's even more load to the alternator. Those higher amp alternators may help but check to see what's the safe limit of your wire harnesses. Check with a pro to see what's more viable to your needs. There are ways around this but it takes a good auto electrician and some money... lots of it. Good luck.  

Alright, I'll see what I can come up with. Thanks.