Battery voltage indicator

The last line of the LCD symbolises the battery voltage:

Filled-in boxes from left to right show the battery status according to "low battery", "critical", "good", "new". In the example in the picture above, three boxes are filled in, i.e. the battery voltage is good, but the battery is not fully charged like new. If the battery status is critical, it should be recharged. If the battery is low, you can expect the device to switch off automatically shortly.