So you have decided to reduce the risk of battery leakage damaging your precious Williams arcade or pinball board by replacing the existing AA batteries with a lithium (CR2032) replacement. Great! Lithium batteries like the CR2032 tend to leak much less than alkaline batteries so this is a good generally a good idea.
Note that I said “much less than alkaline batteries“ – lithium batteries can still leak causing damage to your PCB!
You need to maintain them like any other battery system.
So now the question is, how long will the lithium battery last before it needs to be replaced? I would suggest that you replace the battery as soon as it voltage-under-load drops to 2.8v. Why 2.8? Two good reasons. First, here is a discharge graph pulled from the Energizer CR2032 datasheet: Continue reading Lithium Battery Replacement for Williams and other CMOS Systems