Dont know how efficent it would be, but I have been looking at a 3000W inverter. I have two group 31 batts, 750 cca each, if I hook them paralell to the inverter, then run a charger off the inverter back to the batts, seems to me it would be a self contained absolutly no noise unit. Mount this on the tounge of the trailer in a box. This would be used for lights, fans, drills, small compressor, etc. I also have a 5 hp horz shaft engine mounted on a homemade frame driving a 105 amp leece neville truck alternator that I have used for many years to charge the batts between rnds. It will charge the two batts in the car in about 20 min even if they are down. It runs at idle so it too is very quiet. I used it back in 94 during a 2 week power outage due to an ice storm, with dc lights and accesorys. Sat it and a batt outside and ran wiring through window, only drawback was refueling about every four hrs. (2 Qt tank)
These are some things you might consider too.
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