I have an alienware 17 r2 battery charging don't work (plugged in, not charging) ?

Hi, 

Try doing a power drain. To do a power drain, follow the steps below. 

• Shut down the system, once it’s powered off, disconnect the AC adapter. 
• Disconnect the battery cable (refer to this video for disconnecting the battery cable, it shows how to disconnect the battery cable in the first 35 seconds).
• Disconnect all external devices (USB devices, headsets, external monitors, etc.).
• Press and hold the power button for 30 seconds.
• Connect everything again and turn on the system.

If it is still doing the same thing, please send me a private message with your Service Tag, so we can look further into this.