Replacing the suicide batteries in old arcade cabinets

The term “suicide battery” means - battery on the arcade game motherboard that, when it dies, destroys the game. Why they exist isn't exactly clear. Is it a way to artificially limit the lifespan of their games? Is it an anti-piracy measure? Do they want to assure that they will continue making money from the games by forcing you to send your boards to them for repair after a certain amount of time? Whatever their reasons, we need to save our arcade cabinets.