I had the same problem. I put in a 400 watt power inverter to run my xbox 360. It slowly killed the battery and alternator, and then the power inverter itself went bad. So i got a larger power inverter, added two Optima blue tops in addition to the stock battery, ran the inverter off them as well as the 110v I put in the rear bumper, threw in a battery isolator to protect the stock battery to make sure I can always start, and had a 250 peak amp alternator installed. Problem solved. The only thing I installed myself were the batteries with some thick gage wire because I make a horrible electrician. But I would look into upgrading your entire electrical system to make sure you don't have any issues. Look up OGTerror. He has made MAJOR electrical mods himself. He has a couple pairs of outlets in the center console and a massive power inverter.

 

I have a pretty nice mobile office set up in my Ford. It uses a 300 watt sine wave power inverter. This is best for most sensitive loads...

Here is a link to a good guide...

http://www.outsidesupply.com/definit...ter-guide.aspx

I like hard wiring but sometimes it is easier just to plug into the inverter.