It's clear that you've put a lot of thought into planning your wiring. That, IMHO, is where a lot of the fun of doing it "your way" is! Enjoy the mental excercise. I know I do.
Here is a string I think you ought to read:
http://tnttt.com/viewto ... highlight=
Here is a primer on battery discharge:
http://www.batteryuniversity.com/print-partone-16.htm
Here is another good site:
http://www.schumacherproducts.com/applications/?id=0011
Based upon what I see, you are planning on drawing over 30 amps from your battery for extended periods (more than a few minutes at a time). I don't have any numbers to support my thoughts but in general you can only draw down half of the capacity of a battery before you need to recharge it. So, you have two hours max battery life at your expected draw. Not much, again IMHO. Drawing 30 amps from a 120 amp battery is too much to sustain for long and you won't even get the "rule of thumb" 50% of capacity due to the heat generated. In addition, the inverter isn't 100% efficient and effeciency varies with load. Finally, drawing your battery down frequently will greatly reduce its service life.
Following the guidelines on the Schumacher site it will take a long time to replace the energy you expect to draw from your battery. So, you'll need a lot of power, somehow (via ac charger, tow vehicle, or solar panels), to recharge your battery. More complications.
Why use an inverter at all. Going through multiple voltage conversions is not efficient. Why not use a 12 volt power supply for your computer, a 12 volt fan, a portable radio with 12V input, and a 12 volt charger for your phone. 12 volt doodads are usually designed to use less power (yeah they're not as powerful as 120 volt doodads but they can get the job done).
The "trick" to running on battery power is to minimize loads. No need for a gazillion watt stereo for some light casual listening in a campground (after all do your neighbors want to listen to your choice of programming). Use a small DC powered radio. Do you really need a fan? I leave my cell phone plugged into my car most of the time I'm out and about and have never even dented the car battery. Don't go through multiple conversions for the computer.
If you have commercial AC available, use it directly without going through the battery and inverter. Saves wear and tear on the battery and inverter. If you don't have AC available, work to minimize your DC load.
In short,
keep it simple and
minimize load. Crusing sailors have learned that doing without AC is much easier in the long run when away from the dock. When at the dock, use the AC as it comes from the plug, not AC to DC, and then DC back to AC.
Hope this helps. There you have it again, the world according to Gus.
Cheers,
Gus
The opinions in this post are my own. My comments are directed to those that might like an alternative approach to those already espoused.There is the right way,the wrong way,the USMC way, your way, my way, and the highway.
"I'm impatient with stupidity. My people have learned to live without it." Klaatu-"The Day the Earth Stood Still"
"You can't handle the truth!"-Jack Nicholson "A Few Good Men"
"Some people spend an entire lifetime wondering if they made a difference in the world. The Marines don't have that problem"-Ronald Reagan