After starting to show symptoms over the past year, my Surface Pro 4 (bought used on eBay in 2017) finally died. The battery bloated out to the point of curving the screen and rupturing the screen adhesives.

At first around August 2020, when turned on for a long time (like 5+ hours), the screen would violently flicker, and it would get back to normal after some rest, and it would repeat.

Then in December 2020 a big spot would start showing up on the left side of the screen:

And finally today I noticed that the battery was bulging.

Oh well.