Problems with iPhone... updating, and battery problems

Aug 16, 2007
So I just got my iPhone two days ago and tried updating it tonight. While I was updating it, it stopped halfway through and said there was "an unknown error." Now I can't do anything with my iPhone. All I can do is turn it on and see the Apple logo on a black screen and reset it using the home button and the power button... that's it. At this rate, I'll be taking it back to the Apple store tomorrow morning unless you guys can help me fix it.

Also, I think I my battery may be bad. When charging, it takes well over 5 hours to get to a full charge and the big battery picture the screen shows when charging always has a little gap, it never glows full.

Any help would be appreciated, thanks.