This topic recently came up and I started looking into it again.nope.The lithium ion rechargeable battery for memory backup needed for this naomi multi?
in-fact most DIMM board have either completely dead batteries or missing batteries.
First of all you might be asking "WHY" you would want or need the battery pack.
Basically the battery stores the last loaded game settings and high-scores. So if you shut down and then boot back up it will go back into the last loaded game, and retain everything as if you hadn't shut down. This wont help you when you change games as all of that will get wiped out, but it's nice if you run 1 game for a while challenging yourself to get higher scores, or want to run a DIMM based setup in an arcade where it's loading the same game every time.
There are some solutions already
I know that other's like FrizzleFried have come up with a "semi-perminant" solution to the DIMM battery problem
There are also guides on how to rebuild the battery pack utilizing the protection circuit from the original battery pack.
A less DIY and More Drop-In Solution
I'm not really a fan of either of the above solutions. Ideally, I'd like a nice new Battery pack with a protection circuit already built in that at most only requires changing the connector. Searching around I found this on AdaFruit: https://www.adafruit.com/product
/354?gclid=CjwKCAjw96fkBRA2EiwAKZjFTeGE0x0A7kVFRuFYw7eupNC3krP1uVFd1CiROjt5W4PeZ77tyKg8LRoC6boQAvD_BwE
This appears to have the same type of cells as the original battery and has a built in protection circuit, however it has no thermal protection and advises limiting the charge current. I'm unsure if the original batteries have thermal protection and I have no idea what the charge current is on the DIMM boards.
If you know the answer to either of these questions or know of other dual-18650 based battery packs please post up below!