try to enable BT.In my case that fixed the battery problem

@ D.K. wrote:

try to enable BT.In my case that fixed the battery problem

How to flash back to a previous BIOS version:

BIOS Back Flash
- Completely shut down the device.  
- Press the Novo Button :  It is the small reset hole on most devices that you need a unfolded paperclip to reach.
- If you're device does not have a Novo Button, then pressing F1 or F2 repeatedly on startup will take you into the BIOS. 
- In the "Configuration" Tab, set "BIOS Back Flash" to "Enabled"
- Click the "Exit" Tab and click "Save Exiting Changes" or Press "F10"
- PC will Restart and enter the Windows Environment.
- Head over to the Support Page for your device.
- Under Drivers & Software, Manual Update, then BIOS section, you can find the latest BIOS version.  
- Expand the BIOS driver with the down arrow. Right Click the download icon, then select "Copy Link Address"
- Paste it into the URL section of the browser
- Change the nr of the bios version  (ex: 8HCN36WW  to 8HCN35WW or 8HCN34WW) and hit enter.
- Do this in the URL input section of the browser until you find the previous BIOS version to download.
- Right click the file and select "Run as Administrator"
**Note: You can also attach the file to a USB flash drive, boot from USB through BIOS and then run it that way.
**Note: Make sure the AC adapter is connected and that you have at least 30% battery charge when performing this update.

Hope this helps

Regards

Voithos