I experimented with the supply voltage of the oscilloscope by connecting it to a laboratory power supply. The oscillograph works normally at a voltage from 9 to 16.8 volts, I was afraid to give more, not knowing what circuit it has at the power input. But since it is normally powered by 15 volts on its native power supply, it means it should also withstand 16.8V.
The minimum voltage at which it still remains operational is 8.5 volts, but this is already on the very verge of shutting down; as soon as the voltage drops a little lower, the oscilloscope reboots.
Power consumption is approximately constant - about 36.5 watts with the oscilloscope application running and about 31.2 watts with the application closed. But a force-closed application automatically restarts after a while
This all means that the oscilloscope can be powered from both a 4S battery (12-16.8V) and a 3S battery (9-12.6V).
The voltages shown in the photo on the power supply are inflated to compensate for the voltage drop on the wires. At the same time, the oscilloscope received almost exactly 9V and 16.8V.