If you're experiencing a battery that drains fast or doesn't charge, make sure the battery is left to fully charge overnight. When plugged in the LED will turn red and turn off when fully charged. It should take about 2-4 hours to achieve a full charge.

Does the unit power on with the AC adapter? This unit bypasses the battery when plugged in.

Is the unit being powered off/shut down? Keep in mind it still uses power while in sleep mode. Power off vs Sleep mode:

• When the unit is on, press the power button to put it in sleep mode.
• To shut down, hold the power button for one second until the "Power Off" dialog box appears on the touchscreen, then tap Power Off.
• To perform a hard power off (without shutting down the software), press and hold the power button for five seconds.