Do the N64 cartridges have batteries?
 

Morbid curiosity, but has anybody taken apart a Rare, or rather, Banjo game pack? Do they have the button cell batteries that some games do to hold the save data? Might it be possible to wipe them (including the SNS unlocks) by removing/replacing the battery?

Yes, they do.

On this episode of RWP, Whyme destroys his BK-cart with a hammer and discovers a small mystery egg with question marks has fallen out where the battery should be.

https://www.models-resource.com/reso...s/23/22328.png

You know the battery from B-K cart was split into three parts. First one is located in unaccesable cave called Sharkfood Island in Treasure Trove Cove. Second one can be found behind unbreakable icy wall in Wozza's Cave. And the third part is hidden behind unopenable door in Gobi's Valley. Hurry up and find them before your saves will be lost! :p