Fake battery loading and testing

For some test cases having a fake battery will allow to test how the system responds under certain conditions. For this reason a fake battery is provided for the x86_64-linux targets. It is automatically loaded on the laptop profile when it is determined that there is no battery available on the device.

ssh ghaf@ghaf-host
systemctl status create-fake-battery.service

This will show if the fake battery service has been launched and what is the current status of it.

ssh ghaf@ghaf-host
sudo modprobe fake_battery

This will allow the battery to be manually loaded.

cd /sys/class/power_supply/
ls

If the battery is loaded there will be a fake-battery directory present in that location.

[ghaf@ghaf-host:/sys/class/power_supply/fake-battery]$ ls -al
total 0
drwxr-xr-x 5 root root    0 Sep 15 12:27 .
drwxr-xr-x 3 root root    0 Sep 15 12:27 ..
-rw-r--r-- 1 root root 4096 Sep 15 12:27 capacity
-rw-r--r-- 1 root root 4096 Sep 15 12:27 charge_full
-r--r--r-- 1 root root 4096 Sep 15 12:27 charge_full_design
-rw-r--r-- 1 root root 4096 Sep 15 12:27 charge_now
-rw-r--r-- 1 root root 4096 Sep 15 12:27 current_now
-rw-r--r-- 1 root root 4096 Sep 15 12:27 health
drwxr-xr-x 3 root root    0 Sep 15 12:27 hwmon6
-r--r--r-- 1 root root 4096 Sep 15 12:27 manufacturer
-r--r--r-- 1 root root 4096 Sep 15 12:27 model_name
drwxr-xr-x 2 root root    0 Sep 15 12:27 power
-r--r--r-- 1 root root 4096 Sep 15 12:27 present
-r--r--r-- 1 root root 4096 Sep 15 12:27 serial_number
-rw-r--r-- 1 root root 4096 Sep 15 12:27 status
lrwxrwxrwx 1 root root    0 Sep 15 12:27 subsystem -> ../../../../class/power_supply
-r--r--r-- 1 root root 4096 Sep 15 12:27 technology
-rw-r--r-- 1 root root 4096 Sep 15 12:27 temp
-r--r--r-- 1 root root 4096 Sep 15 12:27 type
-rw-r--r-- 1 root root 4096 Sep 15 12:27 uevent
-rw-r--r-- 1 root root 4096 Sep 15 12:27 voltage_now
drwxr-xr-x 2 root root    0 Sep 15 12:27 wakeup68

This lists all of the properties for the fake battery device which can be read and written to. It is of course only possible to write to properties that have rw permissions.

[ghaf@ghaf-host:/sys/class/power_supply/fake-battery]$ cat temp
300

[ghaf@ghaf-host:/sys/class/power_supply/fake-battery]$ echo 100 | sudo tee temp
[sudo] password for ghaf:
100

[ghaf@ghaf-host:/sys/class/power_supply/fake-battery]$ cat temp
100