I don’t think it’s going to work as intended with the s905x-cc.
You can make a button halt the machine, but not turn it completely off, or back on. This requires a Device Tree Overlay. I haven’t done so, but I have read that it is possible.
Also, If set to input, and pulled low pin 15 will reset the board while it’s running, but not from a halted state. Once halted, only power-cycling the board will boot it again.
I have no idea whatsoever as to how to accomplish this on Batocera, by the way. I have I’ve messed around a little using SSH, but haven’t got far yet. I really hate pacman. It’s a shame they took obvious good name for a package manager.
See here for answers from more knowledgeable people than I:
EDIT
@freezr: That’s normal behavior. See the second link above. Again, I don’t know how to do it on Batocera directly, and I run that os on a different board anyhow. I can tell you that you log into Batocera as root, so you should skip the sudo in the above command. I really wish these kodi/retroarch type os’s would give us a CLI that we don’t have to access remotely.