I finally got a iPod Touch! =) Question.

So, I did it. I decided to buy a iPod Touch, but a used 2nd generation 8GB. Only for $145, and it is in very "mint" condition, since I know the owner who had this previously before me. It is fantastic! I never go anywhere without it. It's very useful, and I love the fact it has YouTube on it. ;)
So one question, the battery life.. I still have a warranty under it until September 2010. I am wondering if I should go ahead and test the battery at a Apple Store to see if I need a replacement. If I do need a replacement, they will give me a brand new iPod Touch.. How do you know if the battery life is about to diminish? I know my boyfriend's iPod Touch lasts a couple days with the battery fully charged. Mine can't. I'd have to charge it 2-3 times a day just to be able to be on it all day. I do know the battery on it does run out very fast if I am constantly on it.
Thoughts? Opinions?

I usually plug mine in when I am at the computer, just to be sure, so don't know how long the battery would last without doing that. But I have had mine since it was brand new, and if Paul and I use it to, for example, play Scrabble while we are killing time waiting somewhere, it can run down the battery after an hour or so.

This sounds really stupid on my part, but when I first got my 1st generation Ipod touch, I didn't know how to turn it off completely and it would be on all day playing music in my bag or whatever. I learned later on that you need to keep holding the top button down for a few seconds and you'll get a screen that says slide to power off. Now the battery can last me a few days when fully charged. I doubt this happened to you, but I never read instructions, so that may explain my ignorance. Also, if you have a warranty I say go for it, you have nothing to loose.