Hey guys i am have a Blackberry 9500 storm and vodafone SIM in it.I don't know why the battery gets dry twice a day.
i tried everything possible to tackle this problem but nothing worked.
I also tried a security wipeout and memory cleaning but still no change.
Now i downgraded my phone OS to 4.7 but still the same problem is there.
I recommend you to send it to technical support, this worked for me, I did recieve a new BB from them.
If you don't have warranty, get a new battery to check that it's not a problem from the device. If you still have drain problems with your battery, buy a new mobile.