This article only applies to: Predator 17 models.
Some Predator 17 models have a switch that will disable the battery when the RAM and hard drive access door is not installed correctly. This will prevent the system from turning on using only battery power. It will also cause the system to shut down if the AC adapter is unplugged. This may occur after the system has been opened to upgrade the memory or hard drive.
You can resolve this by properly securing the RAM and hard drive access door. Make sure the screws securing the door are properly tightened. The image below shows the location of the switch that disables the battery.