The CPS-2 arcade board contains a suicide battery that will force the board to kill itself when it runs below a certain power threshold.
Supposedly this was created to mitigate piracy of the games, as well as bootleg boards, but wouldn't bootleggers just make their boards without the suicide system?
In addition, once the battery runs out on an official board it no longer works, which makes its inclusion even more puzzling. What was the point of this?