X1 battery discharging stuck at 7%

The old battery of my X1 Carbon 4th Gen. was dying, and the battery readings became unreliable. So I had it replaced (with an official battery replacement). Now the problem with the old battery and new battery (thus it's some calibration problem, and not one inherent with the battery) is the following: When I discharge the battery, the battery reading becomes stuck at x% (currently at 7%) and does not drop further. I can still use the laptop for hours; until it suddenly drops to 0% and my laptop shuts down. sudo tlp-stat -b shows me without changing /sys/class/power_supply/BAT0/energy_now = 30

Question by jabberwocky on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.