As to an inverter setup, many choose to go the cheap route and purchase a small inverter from their local walmart. The cheap ones do one thing, they take DC current, from a battery and convert it to AC current (household) that can run TVs, blenders, and such. They will typically use a technology called square wave. While square wave will work sometimes sensitive electronics don't like it. Real household current is sine wave current and works better. Many get along fine with squarewave though.
With this type of inverter, you still need some way of charging your battery when it gets depleted. Obviously, you wouldn't want your battery to die during your tailgate so you must size your battery appropriately. I'll get into batteries later. To charge your batteries, you can just purchase a battery charger and hook it up when you get home using alligator clips. The better solution is to purchase a battery charger that is permanently hooked up where you just plug your setup into a wall outlet and leave it so it will be ready to go when you need it.
These inverters are rated in wattage so you need to figure up what you want to be able to run simultaneously. All your items you want run will have a rated wattage so you need to just add up all the wattages. Some things will have a starting wattage which will be higher. I can't think of anything off the top of my head that has a high starting wattage that would be used for tailgating but you need to keep this in mind. Most inverters will allow for some over wattages for a brief amount of time, under one second. Again, starting loads typically are not found in a tailgate situation so I wouldn't worry too much about those. I do think it's important to over size the inverter slightly, like 10-20%. So if you add up everything you want to use and it comes to 500W, go ahead go with the 750W model.
Now to batteries. Remember that the batteries are your fuel tank. Just like in a generator your fuel will eventually run out. Obviously you can't pour fuel into the batteries like you can a generator's fuel tank. So, having enough battery (fuel) to last all day is crucial for a good setup. This can be calculated as well. Batteries have an amp/hr rating, (similar to gallons of fuel in a tank). Each appliance you want to hook up has an amp rating as well. There are formulas on the internet to help determine how much battery capacity you need. One 12V Marine deep cycle will probably not get it done. Most of the nicer setups use 6V golf cart battery setups wiring two golf cart batteries in series and then multiple pairs in parallel. I prefer AGM batteries because of their long life span and how well they perform with many charge/discharge cycles. They do cost a lot more though. My guess would be if you had four 6V golf cart batteries that would make for an adequate setup.
Another thing often overlooked is battery cable size. You have to use big wire. I would use #6 stranded wire at a minimum. I use 4/0 for most of my setups but the inverters I use are typically 3000W setups. Also, it is important to fuse the main battery leads. On my big setups I use 400AMP fuses. In a small setup 50AMP should be sufficient. You can purchase a 50AMP auto-resetting circuit breaker at most autoparts stores. It is also important to use crimp or solder on terminals on all your connections. Simply stripping the wire back and shoving it under a wingnut is not the way to do it. Alligator clips suck as well.
If you really want to do it right, you can purchase a inverter/charger. They are significantly more expensive but they do everything. You can just plug them in and they charge the batteries and maintain them as well when not in use. You can also get a remote panel to monitor the status of everything.
The secret to a good setup though is permanently mounting the whole system. Batteries should be strapped down in battery boxes. The charger and inverter should be screwed to a board or something. They can get warm during operation so ventilation is a key as well. I've seen some really good systems mounted to one of those baskets that slide into a receiver hitch on a car. While quite heavy it worked really well and was very portable.
I realize this is probably not as convenient as a generator but having a power source that is almost completely silent and not having to deal with gasoline is pretty cool. Anyone interested in putting a system together, I'll be happy to offer advice.
