Firstly, how old is your battery? Could be time for a change??? You may find some other threads talking about checking CPU consumption and battery usage. Also, you could install BatteryGraph to see what's draining the battery. But basically, if you run PR1.3, with wifi on 24/7, battery life could drain within 1-2 days. From my experience, GPS tends to consume battery life - so, turn off GPS applications if not in use.