V-lock battery plate Fotga ccUPS III 8.0V instead of 8.5V

[frank10]

I bought this battery adapter to have several V output from a V-mount battery: 14.8V, 12V, 8V, 5V
The problem is I have a GH5 and in the insertion it was written it is compatible: instead I discovered GH5 doesn't power up if Voltage is under 8,2V (battery at charged level), so it must be, externally, about 8.4-8.5V upto 9V...

These are the pics of the board:
(If you need more detailed pics, ask me, thank you.)


Rough looking at it, do you think it's a good power circuit?
Is it possible to modify the circuit to have 8,5V instead of 8V?


EDIT:
We are talking of this unit:
https://www.amazon.com/Supply-System-Adapter-Charge-Battery/dp/B01B6011GO

[willyfan]

I explained to you in another forum, but I replay here for forum users.
You can change the SMD resistor R21 with a 7,8k new resistor. Code is 87B. I'm not sure what voltage you can have with this modification but I think that is around 8,7 - 8,9 volts. If you want have a better precision, you can put in the circuit a 5,2k resistor and a same value (5,2k) multi-turn trimmer series connected, so you can regulate voltage from (around) 6 to 11 volts.

[frank10]

I add here too, other detailed photos:
http://imgur.com/a/AiYYF

I tried with 7.5 kOhm (752) and the output Voltage became 8.5V: tested on GH5, it works perfectly!
Thank you a lot for the suggestion.