Yes, I was about to suggest that, using a RV AC to DC converter. The Marine/RV batteries are designed to be fully drained unlike a car battery. Do you have a multimeter to test the output of your RV's DC power supply? Less than 13.5V should be good. The RV's DC supply should work great because of the DC motors (water pumps) that require large instantaneouse amperage. I am very new to RC electric heli's but I do have a lot of electronics experience, so I would imagine that your heli's motor is going to scream at 13V compared to 11.1V, that and think how wild things could get if you didn't have the weight of the battery.