I have a Dell and can say I have left it on for long periods of time, sometimes until the power is drained and it shuts down. Recently I have noticed the power slowing down as I have fully charged it multiple times. It used to max out at 2 hours but has slowly made it's way to 20 minutes. I also found myself recentlyangling the AC cord in the back to keep a steady charge. The cord became harder to connect over time as well. Before you know it my CPU was dead but my AC power cord remained green. Is there a chance my battery is dead and needs replaced or I need a better AC pwer cord Connection. Or could it be something worse?