Ipod battery running time? wtf

[Grip72]

ok so i just bought a 30gb ipod video and i'm very tempted to take it back.

i've only used it twice now.

I charged it fully the first time and i got about 3.5-4hours use of it then the battery died. that was it.

Then i charged it fully again and this time the battery lasted about 4-5 hours.

The salesdude AND the website says the battery should last about 14hours but it will deteriate after a few months or a year or so.

so, do you guys think I got a faulty Ipod and I should take it back? or will i end up exchanging it and having the same "problem" with this lack of battery run time?