Created attachment 726715 [details]
screenshot of VTY during the crash

A few seconds after I unplug the power cord, my laptop starts lagging and
freezing more and more until it becomes totally unresponsive.

The first symptoms are : applications cannot be launched or closed anymore,
gnome-shell starts loosing GUI items, etc.
Then the gnome-shell session crashes and in return VTY also become unreachable.

On the VTY, the following messages appear :

 - ata2: COMRESET failed (errno=16)
 - systemd-journald complaining it cannot write logs.

< A photo of the error messages is enclosed here >

Same pattern if I try to boot straight on  battery power. It fails either early
in the boot process or at the login screen.

Looking around for the "COMRESET failed" message, I did the following :

 - update the SSD firmware update to the latest version ;
 - update the UEFI (Thinkpad T460)

Also, note that I freshly install Tumbleweed on Friday.

Before, I was on Fedora and never had this issue.

So, except a weird coincidence, it is unlikely to be hardware related.
Moreover, if my SSD was dying, why it would have no error in SMART and it would
fail only on battery power.