you guys might want to check out the "trigger cables" that pull higher voltages off of USB-C PD batteries. most can do 12V, some up to 20V
https://www.amazon.com/2-Pack-JacobsParts-Type-C-Trigger-Connector/dp/B08NTVLZH7
the cheap and common 10000 mah batteries run my preamps and adcs well over 5 hours
Be very careful with that.
Just checked this link. Without modification that cable will not work and will likely damage the R-44 as its output is center pin positive. I assumed there was some sort of voltage converter built into the cable, but it it seems the variable voltage thing is something the battery does. Tread carefully.
"Performs PD or QC power negotiation"
Don't let the magic smoke out of your R-44. A Talentcell like jbell's are a known-good safe bet that lots of tapers use.
trigger cables actually have a chip in them, either fixed, or larger ones have selectable voltage via either a mple one or two button interface, or in some cases a display..
I assume anybody using one would check voltage with a meter and understand the difference between center positive and the less common center negative
wrong voltage and polarity is dangerous to gear regardless of source, that said, the trigger cables are no more inherently dangerous, you still need to know the parameters of the power source.