@hellp this one: easy fix but so annoying

Linux command to find serial number of Lenovo laptop

$ sudo dmidecode -s system-serial-number

Schon mal gute Erfahrung mit einer Thinkpad-Reparatur/Upgrade gemacht. Sympathisch und flexibel. Preise auch gut.

Use:
$ sudo module-assistant a-i tp-smapi

and set in /etc/sysfs.conf:
devices/platform/smapi/BAT0/start_charge_thresh = 40
devices/platform/smapi/BAT0/stop_charge_thresh = 85

The tp_smapi kernel module exposes some features of the ThinkPad hardware/firmware via a sysfs interface. Currently, the main implemented functionality is control of battery charging and extended battery status.