Step 1: Find the name of your battery

We’ll use the upower app to list out all the batteries your laptop has installed. Most laptops these days have just one but my ThinkPad T460s has dual batteries as you can see below:

upower -e

Step 2: Cat the capacity

The file which contains the current level of your battery is stored at /sys/class/power_supply/BAT0/capacity so we can simply cat out the figure into the terminal:

cat /sys/class/power_supply/BAT0/capacity

Show Battery Life Remaining on the Linux Mint Desktop

My use case for getting the battery level like this was because the standard ‘power manager applet’ that comes with Cinnamon likes to freak out on me every now and then. Sometimes it shows the percentage remaining with a dozen decimal places which makes a mess of the panel. Other times it tells me I have a hundred hours of battery remaining and as much as I want that to be true, it ain’t true.

You can use this technique with ZimiZone’s Command result Desklet, just go into the desklet’s settings and add it as a command. It’ll also work with schorschii’s Battery Level Indicator Desklet by going into the settings and adding the path into the ‘Path to battery capacity file’ option (you don’t need the ‘cat’ in this case, just the path will do it).

Check out all the files in /sys/class/power_supply_BAT0 if you need the battery status (ie charging, full, discharging etc), voltage, model, and a bunch of other battery related stats.

ls /sys/class/power_supply/BAT0
alarm                   cycle_count         hwmon2        present        type
capacity                device              manufacturer  serial_number  uevent
capacity_level          energy_full         model_name    status         voltage_min_design
charge_start_threshold  energy_full_design  power         subsystem      voltage_now
charge_stop_threshold   energy_now          power_now     technology