The Air Hogs Aero Aces are probably what you want, and maybe even the Havoc Heli. They are all around $30 each, and they charge right from the transmitter, so all you need are spare AA batteries.

I loved my Aero Ace Biplane right up until I flew it too high and the wind carried it down the road, never to be found again. I got two Havoc Heli's on sale this year for $19.95 each at Toys R Us, and the kids were able to control them pretty well. They don't do well in bright sun, because of the IR remote control, but indoors, or in shade with no wind, they are a blast. They need a thumbtack in the nose to really be able to steer them. I accidently ripped the tail motor off one of them when it got hair tangled in it, but the other still flies great.

Enjoy your camping trip!