Hi, first make sure you really have turned it off. Standby still consumes power, hibernation does not.
Any lights must be off, no heat must be produced.
There are several possible reasons for this behavior.
My suggestions:
1) Check the battery gauge in percents, do not only check the most likely green lamp being turned on. It means nothing, at least with my laptop here and others i know.
2) Take the battery out of the laptop with full battery and check again after a day. Turn it on immediately after insertion of the battery and check the gauge. If it is still 100% then your laptop is the problem as it is consuming power while it should not. I havent seen such behavior up to now.
3) Assuming after that day the battery is as flat as it...