How to view battery information in Linux

Battery information in Linux is provided by the ACPI (Advanced Configuration and Power Interface) daemon which is installed by default in most Linux distributions. Monitored battery information is stored in the /sys filesystem.

You can view your battery information by viewing the content of the files in the battery section of the /sys filesystem or by using userland applications such as upower or acpi.

Battery information in /sys filesystem, upower or acpi can be viewed from the terminal in Linux.

1. Launch a terminal application.
2. View available battery informations in /sys filesystem.

   $ ls /sys/class/power_supply/BAT0/
   alarm           charge_full_design  device        present        technology          voltage_now
   capacity        charge_now          manufacturer  serial_number  type
   capacity_level  current_now         model_name    status         uevent
   charge_full     cycle_count         power         subsystem      voltage_min_design

3. View battery informations from any of the files.

   $ cat /sys/class/power_supply/BAT0/capacity
   100

4. View battery details using upower.

   $ upower -i /org/freedesktop/UPower/devices/battery_BAT0
     native-path:          BAT0
     vendor:               Samsung SDI
     model:                DELL TXF9M6C
     serial:               34075
     power supply:         yes
     updated:              Fri 05 Jul 2019 11:27:48 AM +08 (91 seconds ago)
     has history:          yes
     has statistics:       yes
     battery
       present:             yes
       rechargeable:        yes
       state:               fully-charged
       warning-level:       none
       energy:              54.0968 Wh
       energy-empty:        0 Wh
       energy-full:         54.0968 Wh
       energy-full-design:  61.9932 Wh
       energy-rate:         0 W
       voltage:             8.504 V
       percentage:          100%
       capacity:            87.2625%
       technology:          lithium-polymer
       icon-name:          'battery-full-charged-symbolic'

5. Install acpi userland application.

   $ sudo apt update && sudo apt install --assume-yes acpi # Ubuntu and Debian

6. View battery charge information using acpi.

   $ acpi
   Battery 0: Full, 100%

7. View detailed battery information using acpi.

   $ acpi --battery --details
   Battery 0: Full, 100%
   Battery 0: design capacity 8157 mAh, last full capacity 7118 mAh = 87%