I had an issue with my blackberry not starting at all. I finally fixed it as it was a flat lined battery but now it keeps draining the battery in less then 8hrs. I have new battery aswell. I have to leave it on charge otherwise it will die and will not recharge unless I do the bAttery pull.

Does anyone have any ideas how to fix this issue??

If it's not simply a defective battery and it's new, I would return to the carrier for a replacement.

Not possible. I got this one off a friend cheap.

Maybe a format and reload the os?

I was also experiencing a sudden quick battery drain after the upgrade to .148. I followed this problem in a couple discussion threads. Seems pretty random, some have the problem and others didn't. This was a very real problem on my phone. Reading all the other threads, the pattern seemed to be around a few apps. I removed the follow apps and the battery life is back to normal:
Weatherbug (I believe this is the main culprit)
Vcast
Poynt

My battery was draining fully after only 8 hours, and now it's been 12 hours and I'm still at 80% charge. Other then this battery issue, the .148 upgrade has been a big improvement on my phone.

Thanks to all for the helpful analysis and problem solving!