Onion Omega2 Documentation

The Omega’s LED

turn OFF
echo gpio > /sys/class/leds/omega2\:amber\:system/trigger
fast-gpio set 44 1

turn ON
echo default-on > /sys/class/leds/omega2\:amber\:system/trigger
fast-gpio set 44 0

Expansion Dock


The RGB LED on the Expansion Dock consists of three LEDs that give you the ability to create RGB colors on the Expansion Dock.
GPIO 17 controls the red LED. GPIO 16 controls the green LED. GPIO 15 controls the blue LED.
The RGB LED is active-low, meaning that setting the GPIO to 0 will turn on the designated LED.

So in the next commands n must be 17, 16 or 15
gpioctl dirout n

turn OFF the R, G or B LED
gpioctl dirout-high n
fast-gpio set n 1

turn ON the R, G or B LED
gpioctl dirout-low n
fast-gpio set n 0

See also Using the Omega’s GPIOs

On Omega2 with 0.1.10-b160 firmware the above commands should work for you too ;-)
I don't fully understand what does the 'BATTERY LED' or the 'BATTERY LEVEL' tag mean here.