My samsung omnia7 lost 37% of battery in 10-11hours when the screen is locked and im not doing anything with it except mayb when my alarms rang twice. Is 37% in 10-11hrs alot??
Check all background applications running, Bluetooth, GPS, Data connection, email syncing timeframes, etc. Battery usage can be anywhere from 1-3% per hour depending on your settings.
I had battery issues with my HTC Arrive after Mango. I tried everything I thought and then I decided to to a phone reset and now my battery life is back to normal.
Sure, re-downloading all your apps and re-setting your settings is a pain in the butt but it was well worth it for me!