I'm quite worried about my battery. I charged it overnight so this morning it was fully charged. I've only used it for maybe 2 hours today and it's at 32%.
Bluetooth off, location off etc.
It seems to go down maybe 10% in about an hour when I'm not using it.
10% an hour whilst using it is normal as 10% x 10hrs = 100%
If your not using it then there's something going wrong.
If its jail broken I would suggest you check whats running in the background. It would also be worth doing a hard reboot to flush any sort of background processes or memory leaks that may be running down the battery.