Samsung SP-P310ME - Manual (Page 12)

LED lights up red.
This displays the remaining battery power in a percentage.
To check the remaining battery power, press the PUSH button at
the bottom right of the battery pack. The remaining battery life is
indicated with the blue lamp and the blue lamp turns off after
about five (5) seconds.
When the AC power is connected through the adapter, the blue
LED lights up if charging is completed.
Battery Installation and Precautions.
1. Installing the Battery
Place the projector over the battery and push it down while pushing the back of the projector forward. When the
projector is connected to the battery, the screen is displayed automatically. Do not look directly at the lens while
connecting the battery.
2. Removing the Battery