On the subject of suicide batteries
I think that the original 'Bounty' by Orca might use one.
Shoutime said that he could see a battery, and if you compare the set 2 in MAME with the one that works it seems the main difference is that the startup code in set 2 seems to be hardcoded to draw an Orca logo and nothing else.
I suspect that the module on the PCB overlays the first part of the program rom, I also suspect that the parent set in MAME is a bootleg.
Since the game is from 1982 I'm not really sure we'll see a dump of whatever that battery was keeping alive if my theory is correct ;-)