My wife has an older steel two horse Thompson trailer..  It's just a bed and closet but it's better than a stock trailer..  I was thinking of installing a window a/c under the neck..  which is pretty straight forward, I have a generator (6K) it's a noisy one..

  My concern is running the gen. at nite during trail rides.. I'd rather not, what if I run the gen during the day and at night use an inverter (a big one) just to maintain the cool?  I think two deep cycles and a 3k inverter will do..  Has this been done or am I crazy? 

 For more than one night stays I could recharge the batts. during the day W the gen.....

   Thanks for any help, I'm handy with electricity and mechanicals, but new at horse camping and not pissing people off!

You may want to consider running 2 6 volt golf cart batteries in series for 12v. Your batteries wouldn't last more than 2 or 3 hours even with that set up running a 3k inverter and a/c, IMO. Seems like a large expense for not a lot of benefit. Honestly, at night here in Ohio it gets down to the upper 60's/lower 70's in the summer so my wife and I hardly run the a/c at night. Just windows and a box fan or a small 12v fan and we're comfortable.

You could look into an inverter generator that is very quiet. Used Kipors and Yamaha's go for about $500-$600 around here. Honda's are a little more pricey.

I only run 1 12v deep cycle most of the time and just running my roof vent fan will kill it in about 2 1/2 hours. I do have a battery charger that charges anytime i'm hooked to electric, but it won't keep up with large draws. Usually if the battery is really low, it takes 12-15 hours to get back to full charge.

We've camped for 4 days on this battery set up running lights, radio, water pump for sink and shower, small fan, and so on. Serves us well. We did run our loud generator in the mornings to cook breakfast and add a little juice ot the batteries, but not more than an hour. It does tend to annoy people.

If the trailer isn't insulated, I would insulate it. It will drop the interior temps down by 20+ degrees in the sunlight. With out it, you're in an oven.