They use a watch (disk shape) battery now and is right about the middle of the right circuit board on my SM.

Do they also use NVRAM now for the high scores/settings, with the battery just for the RTC, or do they still lose settings when the battery is removed?

Hey, I have this same question and didn't see a response. Also, will those "watch" type batteries leak?

If current technology (NVRAM) allows the elimination of batteries, why are they still using them in new pins? It seems like the use of watch-type batteries is a giant step backwards in the name of progress.

Cost. A single watch battery is much cheaper than NVRAM.

What about the leakage question?

Also, does this mean you need to switch out the battery with the game on? I assume yes?

They do leak, but the chances are almost nonexistent, as they are CR2430 Lithium batteries not alkaline. I'd say it's really a non issue compared to AA alkaline or even the older NiCAD batteries.

Yes you have to change with the game on if you want to keep setting and high scores. These lithium batteries can go longer between changes. I change mine every 3 years.

coin lithium batteries only seem to leak when wet. All NES games and old computers have these coin batteries. they are never leaked unless the NES cart looks like it went underwater at one point.

Ok, great. Thanks everyone!

I've made it part of my end of year habits to replace batteries at this time. I have own a WOZ & MMr. If wrong please correct me but both of these have "watch" batteries installed. Looking at this thread and I see that these batteries are considered less of a threat for leakage but still will eventually need to be replaced. So...throwing this out there, how often should these batteries be a concern? Is 3 years too long?

These batteries can typically last 30+ years with no ill effects. See classic NES games. THey still have good CR2032s in them.

Sorry to post on such an old thread - but my CSI Pinball also seems to have another watch style battery on the right side (inside) of the left PCB? It's encased in heat sync like nothing I've ever seen before. It's labeled as

ST (brand> e3 (technology?)
LM338K
9M645 VW
MYS

It's a bit smaller than the CR243X (can't read last character at the moment) and I'm wondering if I have to change both batteries every ~3 years or just the CR243X?

Just did NVRAM on my South Park and replaced the AA batteries on ToM. Maintenance is fun! (right....)

That's a voltage regulator. Not related to the battery.