http://www.addonics.com/products/pow...2v_adapter.asp
fly all day but don't go inverted or you might get tangled up! Sorry, I couldn't resist.

http://www3.towerhobbies.com/cgi-bin...&I=LXRWA9&P=FR
This battery on a 450 size machine would give you a long flight time but not 30 min. and it wouldn't be able to do much due to the weight.