Quoted from radium:Coin batteries will leak. I’ve seen it mostly in laptops. With any type of batteries, there are LOTS of counterfeits now, especially on Amazon. These are really risky. I just buy the lithiums from Home Depot and put them in a remote battery holder. Think I learned this from Pin_Guy
NVRAM is great too if you can install it. I’ve never bothered, no particular reason.
As a guy who works on these pins, I intensely dislike remote battery holders. They are a PITA when trying to take out the CPU to work on it. Plus, the memory is lost if the remote holder has to be removed.
Coin batteries rarely leak. I suspect, when they do, they are not lithium. If AA lithium batteries don't leak, then the lithium coin batteries will not either.
Putting AA lithium in the original holder is OK, but only on the following conditions (IMHO):
* The AA battery holders are in good condition. Most are not. They were cheaply made and fail after 30 years. And most have been exposed to leaky batteries at some point.
* Put a note in the AA holder that only lithium AA batteries are to be used, so that some hapless person does not install alkaline and start the problem all over again.
Since every WPC pin I have ever worked on has had some damage to the AA holder, I just find it easier to clip it off and install a watch coin cell. But don't buy a no-name brand off of Amazon. Too many of them are fakes and not lithium.
https://homepinballrepair.com/how-to-get-rid-of-those-aa-batteries-no-more-ruined-circuit-boards/#watch
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