I can’t find an active thinkpad centric community on here I am just going to post here. My Thinkpad T480s, 16 GB RAM, 238 GB SSD is randomly shutting off while at like 50%. When I try to open it back up it always is dead and I have to connect charger to boot it up again. Why is this happening? Is it battery issue? It complains about not being able to read temp2_input while shutting down and sometimes say PM usage count underflow. Not sure what that is supposed to mean.
It sounds like you have sensor issues. It’s not reading the battery level correctly. You can either remember to start looking for the charger at 60% or look into calibrating the battery sensor or reconfigure your sensors in general. How to do #2 is going to depend on your distro.