Are you sure your laptop is turned off or is it in standby mode? In standby mode it will drain your battery.
Make sure you turn off your computer or put it in hybernaite mode. Alot of laptops are setup if you close your while it is turned on it will go into standby mode.
you can change your settings in the control panel.
How long does your battery last after a full charge while you are using it?
I have this model and with the computer turned off and inside my carrying case, the battery is still drained with I go to use it the next day. Is there anything I can do about this?