Most Thinkpad models since 2012 or so support management of the battery charging system via software. Most wear of Li-ion and Li-polymer batteries is due to charging at battery levels above 80%. (More reading: AccuBattery documentation.) Batteries will last many more charging cycles if you charge only up to 80% rather than up to 100%.

TLP is a toolkit that can handle power saving, including support for Thinkpad-specific battery management. More info: TLP website.

The following steps worked on a Thinkpad E490 (2019 model) with Mint 19.1 (based on Ubuntu 18.04), with kernel 4.15.0-48.

apt install tlp git wget
wget https://github.com/teleshoes/tpacpi-bat/archive/master.zip
unzip -d /tmp master.zip && cd /tmp/tpacpi-bat-master && ./install.pl && cd -
cp /tmp/tpacpi-bat-master/tpacpi-bat /usr/local/bin

tpacpi-bat -s start 1 75
tpacpi-bat -s stop  1 80

The two tpacpi-bat commands need to be executed at reboot; you can create /etc/rc.local (permission 755) for that purpose.

You can see the battery status (and other power management details) using tlp-stat.