Battery Problem ! ! ! HELP

Can anyone help me,,,I have problems similar like this above in this posts...
When i charged my 9700 bold few days agoo ,and when it charge 100% i do the batery pull...and the batery stays alive exactly 48 hours with using the phone like every day..
Yesterday i charge again the phone, and i dont pull out the batery after the charging , and after 12 or 13 hours its say 40% procent ............this is very bad...

Any help???
P.S I dont have any open apliccations or someting like that...

And I do some of recomendations how to resolve this problem but doesen't help any of this..

Do you let the battery drain all the way down that's not good, how long have you had the phone or that battery. Could be a bad battery. Have you tried updating the software. If you have updated software and no apps running its the battery and you probably need a new one.

Posted from my CrackBerry at wapforums.crackberry.com

I have the phone 3 mounths ,and I took it brand new..
Also I updated OS one week ago to T-mobile 5.0.714

But how can be everyting allright with baterry when I pull out after charging and it drain after exactly 2 days with watching videos on youtube ,,and doing many other things -mail,messenger etc...

Posted from my CrackBerry at wapforums.crackberry.com

make sure you arent running anything in the background that isnt needed all the time....

hold down the BB button, new pop up appears.... if anything other then Browser, messages, phone, bbm, and home are running then open up those other applications and close them out (if you arent needing them)

I don't have anyting open, I know all that steps, I was reading any previous posts which ur familiar with this issue,,but nothing helps.....

Posted from my CrackBerry at wapforums.crackberry.com

Buy a new blackberry

Posted from my CrackBerry at wapforums.crackberry.com

To buy I new blackberry ....you ur joking with me ???the phone is brand new....
Is the new OS update to .714 have someting with this issue????

Posted from my CrackBerry at wapforums.crackberry.com

you can try upgrading the OS, if that doesnt work, try replacing the battery... if that doesnt work then its the device that needs to be replaced...

so start off with wiping and reloading the newest/latest OS
if new OS doesnt work, get a new (OEM) battery
and if the new battery doesnt work, get a new device

now i'm assuming you got this device from your carrier... if that is the case, if you need a new battery, that is covered under the manufacturers warranty, so you can call your carrier and they should be able to send you a new battery