Several eee 900 users experimented this problem when they left their fully charged Eeepcs with the battery plugged in and the power turned off.
After a day resting it went down to 50% and after a couple of days it was all consumed.
It might be a feature of the bios because when you have your laptop turned off you can charge your gadgets and ipods using the usb ports.
The webcam is also a big sink where battery life leaks through so i turned it off in the bios quite easily as i wasnt using it regularly.
I then went and disabled the memory card slot and i experimented a big difference in my power.
So:
Disable those features that you won’t be using in a daily basis (you can turn them on again when you feel the urge).
Keep your battery unplugged and in a cold place, if you are not going to use it in a long time keep it charged at 40% level.
Try installing the 802 bios, they might have solved this issue (not tested yet though).
Get yourself a more capacity battery at eBay.
Go to BatteryUniversity for more tips on power saving and battery health care.
I hope you like this little guide and if you have any questions feel free to ask me.
