You can display the battery status by briefly pressing the power button. The charge level is signalled by three white LEDs:
|66-100%:||all 3 LEDs light up|
|33-65%:||2 LEDs light up|
|11-32%:||1 LED on|
|6-10%:||Warning tone, 1 LED flashes slowly (1/second).|
On some smartphones, the battery level is also shown on the display.