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VivoBook Flip 14 - Battery installed, but not found

Star I

I have an ASUS TM420U-WS51T (VivoBook Flip 14)

The machine appears to boot normally and then after about 30 seconds turns off.  During boot, the battery indicator icon alternates between a charging indicator and then an empty battery with an X in it.  Once booted the Battery indicator does not show in the system tray nor is it available in Settings => Preferences.

Things I know or have tried

  • In device Manager, the ACPI driver is not shown, but can be seen when hidden\non-present devices are enabled. It can be deleted and returns after next boot, but hidden.
  • MyASUS in WinPE indicates the battery is not present. MyASUS in Windows does not offer a battery test.
  • After opening the case and disconnecting the battery cable, the machine works normally.
  • The BIOS is 2.04 but can not be updated without a battery present and a minimum charge value of 20%, though not likely relevant.
  • I have run SFC /scannow and DISM Resotre health. After the former, the machine booted correctly, however after a Windows update it reverted to the prior behavior. I had one other situation where the hardware seemed to behave, but after disconnecting and reconnecting the power it did not.
  • I have tried a hard reset with the power button (hold for 40+ seconds) with no improvement.
  • The PC does NOT crash in the Windows RE environment, but does crash with a Win PE USB attached (Win10XPE).

The battery was running the device for about 6hrs IIRC. It then sat for some time (2-3 mos) and has been problematic since.

The boot behavior and indicators are NOT consistent, in my mind with a failed battery. This typically presents an icon that does not charge and the PC runs normally with power connected.

I am willing to replace the battery, but would like to first validate the battery as the issue.

Does anyone know where\how to purchase this part (ASUS B31N1911).



According to your description, it is indeed possible that the issue you are experiencing is caused by battery aging or a malfunction.
I would suggest you bring back your laptop to our service center for further confirmation.
The following is the contact information: 
Also you can contact the local service center for help.
The following is the contact information:
Sorry for any inconvenience it may be caused.

Star I

Thank you for your reply, but as expected, after talking to ASUS\Microcenter support, depot service on this item is not cost effective.

Other than replacing the battery for about $50, it makes little sense to spend money on this PC and even then it would be preferable to have some more concrete idea of the battery's health.

I was hoping that someone might know if the failure description above is a verified failure mode for the battery or if this failure path indicates other issues.

I was also hoping that there might be some information regarding the battery pin out that could be used for at least Go\No Go testing of the battery itself.                   

I think I can currently provide you with the following for your reference:
[Notebook] Troubleshooting - How to fix the battery cannot provide power/be charged, or be fully cha... 
Sorry for any inconvenience it may be caused. 

Thanks for the ref, but I actually have been through this.

1 - AC adapter appears ok and runs computer correctly with battery unplugged
2 - Reset done, with no change in operation
3 - Unable to update the BIOS. PC indicates it cannot proceed with less than 20% battery power AND AC adapter connected.
4 - BIOS Reset - Done with and without battery connected.  No change in operation
5 - Battery Diagnostics - Battery not found so it will not proceed.
6 - I set show hidden devices and removed the ACPI Battery device and it reinstalled on next boot with no change in operation.
7 - Battery cannot be fully charged is not relevant as the battery cannot be found

Interestingly it does not appear there is a BIOS battery (coin cell) in the device.  While the PC does not reset itself to 1999 or such, it does seem to not track time when not connected to AC.  I expect the last time is written to NVRAM and, if the battery were available, would continue to track time. When running and online, Windows will correct the time. I guess the design saves a couple dollars and in general would work between the battery and Windows NTP and only should need correcting in the case of a failed(?) battery.

Any suggestions on obtaining an ASUS battery in the US? Microcenter will not sell me one unless they install it.