Problem setting max charge threshold with tlp on thinkpad L590 on Ubuntu 20.04
Solution 1:
This is a known firmware issue. From to the FAQ
Charge thresholds shown by tlp-stat -b do not correspond to the configured ones
ThinkPad Edge, E / L / S series, SL410/510, Yoga series
On these models the threshold values shown by tlp-stat -b do not correspond to the written values.
For example the setting
START_CHARGE_THRESH_BATx=75
STOP_CHARGE_THRESH_BATx=80
shows 75 / 74. The described behavior is caused by the firmware (UEFI/BIOS), not by TLP.
Nonetheless the charge thresholds work as configured.