As described in the user guide the power adaptator provide 12V 4A (48V), but if you have a look to usb-c PD3.0 powerbanks most of them provide only 12V / 3A so only 36W or even less.
As discussed here several times (in the correct DHO800 thread), it is actually
not correct that the scope uses 12V when operated on a USB PD adapter. It negotiates 15V, and hence 3A should be enough. The manual is outdated. It refers to the cheap adapter originally supplied by Rigol, which provided a fixed 12V output.
Could I ask that this discussion is kept out of the "Hacking" thread, since it has nothing to do with hacking?