Battery and power status on your CentOS Linux laptop

By | September 2, 2017

The upower cli tool will get you a ton of great info for the battery ( and other things related to power ). Make sure you have it installed ( rpm -q upower ), and give it a shot like this :

$ upower -i /org/freedesktop/UPower/devices/battery_BAT0
  native-path:          BAT0
  vendor:               SMP
  model:                45N1703
  serial:               5616
  power supply:         yes
  updated:              Sat 02 Sep 2017 19:43:02 BST (39 seconds ago)
  has history:          yes
  has statistics:       yes
  battery
    present:             yes
    rechargeable:        yes
    state:               fully-charged
    warning-level:       none
    energy:              21.84 Wh
    energy-empty:        0 Wh
    energy-full:         21.9 Wh
    energy-full-design:  45.02 Wh
    energy-rate:         0.00219125 W
    voltage:             16.237 V
    percentage:          99%
    capacity:            48.645%
    technology:          lithium-polymer
    icon-name:          'battery-full-charged-symbolic'

As you can see after ~ 3 years of extensive use, I should really look for a replacement battery for this laptop, at 48% capacity, its not really doing very well.

To enumerate device paths, use the -e flag like this :

$ upower -e 
/org/freedesktop/UPower/devices/line_power_AC
/org/freedesktop/UPower/devices/battery_BAT0
/org/freedesktop/UPower/devices/keyboard_0003o046DoC52Bx0004
/org/freedesktop/UPower/devices/mouse_0003o046DoC52Bx0005
/org/freedesktop/UPower/devices/DisplayDevice

Now we can check how that external keyboards battery’s is doing

  native-path:          /sys/devices/pci0000:00/0000:00:14.0/usb2/2-1/2-1:1.2/0003:046D:C52B.0003/0003:046D:C52B.0004
  vendor:               Logitech, Inc.
  model:                K750
  serial:               D9ED612B
  power supply:         no
  updated:              Sat 02 Sep 2017 19:59:15 BST (29 seconds ago)
  has history:          yes
  has statistics:       no
  keyboard
    present:             yes
    rechargeable:        yes
    state:               discharging
    warning-level:       none
    luminosity:          80 lx
    percentage:          55%
    icon-name:          'battery-good-symbolic'
  History (charge):
    1504378755	55.000	discharging


Clearly the light in this room, right now, isnt bright enough to be charging the keyboard via its solar cells. Might leave it closer to the window tomorrow.

As you can see from the enumerated list, there is line_power_AC as well as the mouse ( which is actually a trackpad I used ). And if you are so inclined ( I wasent, but just did this for all my laptops.. ) you can track this info and graph it, push it to your monitoring service etc.

from the readme file:
UPower is an abstraction for enumerating power devices,
listening to device events and querying history and statistics.
Any application or service on the system can access the
org.freedesktop.UPower service via the system message bus.

Give it a shot.

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