Jtdcftul

The below command outputs a lot status and statistical information about the battery. The /org/... path can be found with the command upower -e (--enumerate).

upower -i /org/freedesktop/UPower/devices/battery_BAT0

Example output:

  native-path:          /sys/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT0

  vendor:               NOTEBOOK

  model:                BAT

  serial:               0001

  power supply:         yes

  updated:              Thu Feb  9 18:42:15 2012 (1 seconds ago)

  has history:          yes

  has statistics:       yes

  battery

    present:             yes

    rechargeable:        yes

    state:               charging

    energy:              22.3998 Wh

    energy-empty:        0 Wh

    energy-full:         52.6473 Wh

    energy-full-design:  62.16 Wh

    energy-rate:         31.6905 W

    voltage:             12.191 V

    time to full:        57.3 minutes

    percentage:          42.5469%

    capacity:            84.6964%

    technology:          lithium-ion

  History (charge):

    1328809335  42.547  charging

    1328809305  42.020  charging

    1328809275  41.472  charging

    1328809245  41.008  charging

  History (rate):

    1328809335  31.691  charging

    1328809305  32.323  charging

    1328809275  33.133  charging

You could use tools like grep to get just the information you want from all that output.

One simple way: piping the above command into

grep -E "state|to full|percentage"

outputs:

state:               charging

time to full:        57.3 minutes

percentage:          42.5469%

If you would often like to run that command, then you could make a Bash alias for the whole command. Example:

alias bat='upower -i /org/freedesktop/UPower/devices/battery_BAT0| grep -E "state|to full|percentage"'

Add that to the end of your .bashrc file, and you can type 'bat' any time, in the terminal.

There is also a upower -d (--dump) command that shows information for all available power resources such as laptop batteries, external mice, etc.

A friendly reminder: since Linux kernel 2.6.24 using /proc to store ACPI info has been discouraged and deprecated.

Now we are encouraged to use -> /sys/class/power_supply/BAT0.

UPDATE: Linux 3.19 and onwards, we should look at the following directory -> /sys/class/power_supply/BAT1/

For example
checking capacity & status on Arch Linux running Linux 4.20 ->

# uname -a

Linux netbook 4.20.1-arch1-1-ARCH #1 SMP PREEMPT Wed Jan 9 20:25:43 UTC 2019 x86_64 GNU/Linux

# cat /sys/class/power_supply/BAT1/capacity

99

# cat /sys/class/power_supply/BAT1/status

Charging

First install acpi by running this command,

sudo apt-get install acpi

Then run:

acpi

Sample output:

Battery 0: Discharging, 61%, 01:10:12 remaining

Or for a more verbose output that constantly updates:

watch --interval=5 acpi -V

Output:

Every 5.0s: acpi -V                                     Wed Jan  8 15:45:35 2014



Battery 0: Full, 100%

Adapter 0: on-line

Thermal 0: ok, 44.0 degrees C

Thermal 0: trip point 0 switches to mode critical at temperature 127.0 degrees C

Thermal 0: trip point 1 switches to mode hot at temperature 127.0 degrees C

Cooling 0: intel_powerclamp no state information available

Cooling 1: pkg-temp-0 no state information available

Cooling 2: LCD 100 of 100

Cooling 3: LCD 100 of 100

Cooling 4: Processor 0 of 10

Cooling 5: Processor 0 of 10

Cooling 6: Processor 0 of 10

Cooling 7: Processor 0 of 10

Cooling 8: Processor 0 of 10

Cooling 9: Processor 0 of 10

Cooling 10: Processor 0 of 10

Cooling 11: Processor 0 of 10

Thanks to @Wilf this works on my Ubuntu 17.10 on Lenovo Yoga 720:

upower -i $(upower -e | grep '/battery') | grep --color=never -E "state|to full|to empty|percentage"

Output:

state:               fully-charged

percentage:          100%

Or just the numeric value with this one liner

upower -i $(upower -e | grep '/battery') | grep --color=never -E percentage|xargs|cut -d' ' -f2|sed s/%//

It's enough to type the command

acpi

For detailed information you can type

acpi -V

I didn't have to install any packages before.

System:
Debian 7.2 64bit

Maybe you can try:

cat /proc/acpi/battery/BAT0/state

cat /proc/acpi/battery/BAT0/info

Here is an article on a package that can check your battery life at the command line.

Basically, all you have to do is:

sudo apt-get install acpi

acpi -V

I'm a little late to the party but here's my little contribution. Based on the previous answers , I have made a simple script batpower:

#!/bin/bash

# Description: Battery  charge in percentage



grep POWER_SUPPLY_CAPACITY /sys/class/power_supply/BAT1/uevent

The output for executing this ( ./batpower ) is going to be something like this:

POWER_SUPPLY_CAPACITY=23

N.B. : the batery number may be different for you, in my case it is BAT1, but you can always find it out by cd'ing to /sys/class/power_supply or as Lekensteyn mentioned through upower -e

My machine : Ubuntu 13.10 , 3.11.0

Replace BAT1 in the above bash code to BAT0 if you have older version Ubuntu i.e. 13.04 or later.

IMPROVED SCRIPT: Since my original post, I've made a small improvement to the script:

#!/bin/bash

# Description: Battery  charge in percentage



if [ -f /sys/class/power_supply/BAT1/uevent ]

    then grep POWER_SUPPLY_CAPACITY /sys/class/power_supply/BAT1/uevent



else echo "Battery isn't present"



fi 

As always, pay attention to spaces with bash. This is all self explanatory. If battery is present, it will show up, if not - the script will tell you so. Now, go to your .bashrc file and add $(batpower) to your prompt. Here's mine promt:

PS1='[$(batpower)]n${debian_chroot:+($debian_chroot)}[*u@Ubuntu*]:w$ ' 

Update your terminal or open new tab or window, and now you can monitor battery charge constantly in terminal ! including tty ! May the scripting be praised !

Run the following command in a terminal for getting detailed info:

cat /proc/acpi/battery/BAT0/info

If you just want the state do:

cat /proc/acpi/battery/BAT0/state

You can do it without installing any extra packages:

$ echo $((100*$(sed -n "s/remaining capacity: *(.*) m[AW]h/1/p" /proc/acpi/battery/BAT0/state)/$(sed -n "s/last full capacity: *(.*) m[AW]h/1/p" /proc/acpi/battery/BAT0/info)))%

94%

This command is lifted from byobu's source. It might be a good candidate for a Bash alias.

Install acpi, then use watch to continously monitor thru command line.

E.g.

watch --interval=5 acpi -V

will show the information such as below and will update every 5 seconds.

Battery 0: Full, 100%, rate information unavailable

Battery 0: design capacity 6000 mAh, last full capacity 3424 mAh = 57%

Question is why would someone do this?
Well, I have a laptop with broken LCD screen that I am now using as my bittorrent box.

This did the job for me in ubuntu 14.04:

cat /sys/class/power_supply/BAT0/capacity

I was going to suggest acpi but after reading it's not working in 11.10, I had an idea.

Please type this in your terminal:
ls /proc/acpi/battery/BAT0 or BAT1

If you get a "file or directory not found" then this isn't going to work.

But, if it lists files, then here's a script [paste it into /usr/games/ or other directory in $PATH, and run sudo chmod +x /usr/games/batterypercent, or whatever you name it] that I just wrote for you that will give you an estimate battery percentage [See below]:

(Note, if not already installed, install the program calc from the repo: sudo apt-get install apcalc)

#!/bin/bash

math() { calc -d "$@"|tr -d ~; }

cd /proc/acpi/battery/BAT0;

max=$(grep 'design capacity:' info|awk '{print $3}')

current=$(grep 'remaining capacity:' state|awk '{print $3}')

percent=$(math "($current / $max) * 100");

echo $(echo $percent|cut -d. -f1)%

I have tested this script on my laptop. I say estimate above because acpi shows 93% battery, and my script shows 90% battery, so try this script against your GUI battery percentage, and see how off it is. In my case, it seems to be consistently 3% lower than acpi's percentage. In that case, you can add this line right before the last line: percent=$((percent + 3)), where "3" is the percentage it's low by.

**In my lenovo, the battery is listed as BAT1, try that too. (12.04 LTS)

Similar script without calc or apcalc:

#! /bin/bash

cd /proc/acpi/battery/BAT0;

max=$(grep 'design capacity:' info|awk '{print $3}')

current=$(grep 'remaining capacity:' state|awk '{print $3}')

percent=$(expr $current"00" / $max )

echo -e "Current capacity: t$current"

echo -e "Max capacity:  t$max"

echo -e "Percent: tt$percent"

Here is what I use. It just looks at the diff between full charge and current charge as well as seeing if the charge is dropping in which case it uses notify to alert the user.

#!/bin/bash

#

# experimental battery discharge alerter

#

nsecs=3 # loop sleep time between readings

#

ful=$(cat /sys/class/power_supply/BAT0/energy_full)

#

oldval=0

while true

do

  cur=$(cat /sys/class/power_supply/BAT0/energy_now)

  dif="$((ful - cur))"

  slope="$((cur - oldval))"

  if [ "$slope" -lt 0 ]

  then

    echo "*** discharging!"

    notify-send -u critical -i "notification-message-IM" "discharging"

  fi

 oldval=$cur

 sleep $nsecs

done

We can echo just the percentage with that command

upower -i $(upower -e | grep 'BAT') | grep -E "state|to full|percentage" | awk '/perc/{print $2}'

65%

in case you need to extract that value

This won't help everyone, but it did me - I use byobu whenever I am using a terminal, and battery is one of the options for the status notifications bar.

You can either type :

$ acpi -i

Battery 0: Discharging, 98%, 02:51:14 remaining

Battery 0: design capacity 4400 mAh, last full capacity 3733 mAh = 84%

or

$ upower -i $(upower -e | grep BAT)

  native-path:          BAT0

  model:                PA5109U-1BRS

  serial:               FA80

  power supply:         yes

  updated:              lun. 07 janv. 2019 03:54:18 CET (24 seconds ago)

  has history:          yes

  has statistics:       yes

  battery

    present:             yes

    rechargeable:        yes

    state:               discharging

    energy:              39,521 Wh

    energy-empty:        0 Wh

    energy-full:         40,328 Wh

    energy-full-design:  47,52 Wh

    energy-rate:         13,856 W

    voltage:             10,8 V

    time to empty:       2,9 hours

    percentage:          98%

    capacity:            84,8632%

    technology:          lithium-ion

  History (charge):

    1546829628  98,000  discharging

    1546829593  99,000  discharging

  History (rate):

    1546829658  13,856  discharging

    1546829628  14,752  discharging

    1546829597  4,806   discharging

    1546829594  2,678   discharging