11 hours of battery on heavy use? I would kill for eleven hours of battery. I got up at 6 in the morning and by the time I was at work around 8:30 I was down to 50%! What the heck are you doing with yours?
Yeah 11hrs "if I'm lucky" so i usually get 6-8hrs, things you can do is:
Turn off WIFI,Bluetooth,GPS off if your not using none of those features
make sure you have the Display on Auto brightness
there's a setting called power saving mode turn that on
if you see your phone switching 4g to 2g all the time thats a big battery drain
turn 4g off to 2g if your not using the browsing the web or streaming
or get a battery, or return it and go with another blackberry
or maybe you have navigation on all the time.
If you dont mind bulk you can buy this:
http://power-skin.com/battery-cases/ap1515hert/samsung-galaxy-s-tmobile.html