It takes a few charges to get going properly. I went full charge to dead (probably not necessary, but it's a strategy I've come to trust) a couple of times with top-ups in between. I now get a good 24-36hours of 'moderate' use (see thread about 'using as a music player'), but I am careful to turn off those things I dont need (i.e. bluetooth/GPS etc) when they are not necessary.
Hope this helps