How to view battery information in Linux

The ACPI (Advanced Configuration and Power Interface) daemon provides battery information in Linux, installed by default in most Linux distributions. /sys filesystem stores all the battery information monitored by ACPI.

You can view your battery information by viewing the content of the files in the battery section of the /sys filesystem. The filesystem could be hard to navigate, but a few userland applications such as upower and acpi can assist in viewing your battery information.

You can view battery information via /sys filesystem, upower, or acpi in Linux from the terminal.

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%