The hack header is supposed to be usable. I hooked your board's sad and scl to the board and it worked. Once I installed their drivers for the board it stopped, so I think your answer is correct that the pihat is using them as well. I will reach out to the Picade guy and see if his can be disabled s...

Yes it will add the battery monitoring only. I am trying to get this to work on my Picade (8 inch) and nothing works. I tried the psu with a clean install of Retropie and the monitor worked. One I ran the Picade scripts all my controls work with the Picade but I am not getting the battery monitor o...