T 4.9 Disruption of the internal power supply
Using a mobile IT system, e.g. a laptop, requires that the system be equipped with a power supply independent of the power grid. This power supply is mostly designed with rechargeable batteries and normally covers several hours of operation. After this time, sufficient power supply is no longer guaranteed, and so the IT system must be shut down and/or connected to the power grid. The majority of mobile systems continuously checks the supply voltage and indicates critical voltage drops. If this indication is ignored, the system may fail suddenly and the most recent work results in the main memory may be lost.