I suppose I could just leave it on and see if it lasts 9 hours but if it doesnt is there any way to carry a spare battery or recharge it on the plane?
On our road trip, my batteries lasted about 10 hours before I had to recharge. I have a Nano though...I don't know if that makes a difference. Also, I had mine turned up more than normal cos of motorcycle VARRROOOOM noise. The earbuds I had were totally awesome, but I still got some outside noise.
My shuffle does fine for 8+ hours...course I dont charge it til its almost dead