Nothing lasts forever, including laptop batteries. But how do you know when your laptop's battery is ripe for a replacement? Easy: install the acpi package (
sudo apt install acpi on Ubuntu and Linux Mint), run the
acpi -V command, and check the line that looks something like this:
Battery 0: design capacity 4867 mAh, last full capacity 4584 mAh = 94%
In this case, the battery is at 94% of its designed capacity, so there is no cause for concern. If the value is nearing 50%, you should probably start saving for a new battery.
Since it makes sense to run battery checks regularly, you can create an alias for that. Open the .bashrc file for editing using the
nano ~/.bashrc command and add the following alias:
alias chkbat="acpi -V | grep Battery"
Save the changes, reopen the terminal, and run the