my battery okay Need help iPhone 4

6 hours of usage? that seems pretty normal depending on what you do on your iphone. I have done some test on mine, with very light usage (checking every hour). I can get to about 5-6 hours of Usage time before my phone shuts off. with a standby time of 1 day 15 hours.
since you mentioned jb + unlocking, Im not sure, but try restoring your iphone to its factory setting (you will lose those jb and locking). and see if that helps. Ive heard some stories somewhere that the jb caused battery drains on iphones that were jbd.
HP Pavilion DV2812tx, HP DV4-1504tx Windows 7 iPod Hi-Fi, iPhone 4 32 GB Black

My battery lasted like 2 hours after jb and there was a new update to the version and my battery is now almost 6 hours with almost 2 days of standby. I dont know if this is normal but I have been using Internet over the wifi since full charge and my battery is 90% with 50 mins of usage.
Windows 7

yea then that should be normal. evne i get arounde 90% with 50 min. usage on very light, like checking every hour (which is only like 2-3 min. of usage per hour).
HP Pavilion DV2812tx, HP DV4-1504tx Windows 7 iPod Hi-Fi, iPhone 4 32 GB Black