I would check this out before buying a ton of batteries.

https://www.amazon.com/Fxlion-ONE-V-Mount-Battery-Type-C/dp/B07V9FQ2X5/ref=sr_1_15?crid=14SEHX365B1MI&dchild=1&keywords=v+mount+battery&qid=1616892693&sprefix=v+mount+%2Caps%2C205&sr=8-15

I use this Vmount battery D-tap to dummy battery as it has Voltage monitoring with D-tap , USBC and USB A.

Hopefully this can help a bit

https://www.amazon.com/Fxlion-ONE-V-Mount-Battery-Type-C/dp/B07V9FQ2X5

FYI, the USB PD output from that is only 9v/2a. Sony stipulates 9v/3a.