When running Linux on a laptop (other than a Thinkpad), battery backup time is just about 120 to 150 minutes, irrespective if it is used for heavy work or just idling.
To increase the battery backup time in Linux Mint 20+, open a terminal window and install the tlp utility as below:
$ sudo apt-get install tlp <enter>
After this, start it using:
$ sudo apt-get install tlp <enter>
$ sudo systemctl enable tlp <enter>
Additionally, install the cpufreq utilities to squeeze more battery time by setting powersave or performance mode for the CPU. To do so, do the following:
$ sudo apt-get install cpufrequtils indicator-cpufreq cpufreqd <enter>
Reboot the laptop and wait for a few days to experience enhanced battery backup time.
To check status:
$ sudo tlp-stat -s <enter>
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