for the last few days it started to start up automatically after midnight about 2-3 am and stays at the logon screen.
the problem is its drains my battery while i am asleep and in the morning when i take it work it shows almost zero battery.
I would do as chainzsaw says and go into your BIOS but also look for the wake on options. Things like wake on lan can be a nuisance. For instance I can switch on my comp just by activating my squeezebox.