I have a Dell Precision M70 laptop. My question is about my battery. The battery is brand new and it holds a 3 hour charge for quite a while. My question is that when I shutdown my system and then try to start it up using the battery and no AC power it won't turn on. If I plug the AC power cord in with power, then the laptop will boot up. While in windows I can unplug the AC cord and run on the battery which has a full 3 hour charge. Should I take the battery out and use an eraser on the contact points? Or is there some setting I have overlooked? Or should I shutdown the laptop with the AC cord unplugged to boot up with the battery? I am lost at this point because the battery is good. Any advice would be appreciated.