Nokia Nseries :: N8 - How Long Can Listen To Music

I am a Nokia n8 user and I am pretty happy with it ( Wouldn't trade it for an Iphone ) . I am going in a trip soon and I would like to know if I can listen to Music on my N8 for around 6-7 hours without recharging. I am going to use Pioneer SE-M390 Headphones and I'd like to turn the volume very high ( Maybe Max ). Do you think my phone can handle it? I have recently deleted all widgets and turned off all background apps . With energy saving mode the phone survies decently a few days ( it simply stays unused ). Do you think I should better buy a MP3 Player? The ones I have been looking into are pretty expensive and I thought the phone might be good too since the sound is superb and has a lot of memory. Also during the camp I might be the "DJ" with the Radio FM transmitter. Plugged in with the charger would it be able to transmit continuously for 8 hours ( I dont want to burn it =D ). Further more I would also like to buy a MicroSD Card , a Sandisk Ultra 32gb ANDROID. What does the Android stand for? On Sandisk's site it says it is specially designed for Android phones. Does it mean I cannot use it with my N8 ( Belle OS ) ? I dont wanna spend 60$ for something useless. Some guys said I can "Format" the MicroSD to get rid of the "application for Android" located on the MicroSD.