How to Change Game Boy Cartridge Battery : 8 Steps (with Pictures) - Instructables
Preservation project. I'm upgrading old NES and SNES cartridges with better eprom batteries and battery holders. You'll lose your save games with the mod, but get years more use from old games.
Amazon.com: 12Pack CR2032 Battery, CR2032 3V Lithium Battery with Solder Tabs for SNES, N64, Gameboy, Pokemon, Gameboy Color Game Battery Replacement : Video Games
GameBoy Color games do not save any more - Retrocomputing Stack Exchange
Replace Gamesave Battery
How to Change Game Boy Cartridge Battery : 8 Steps (with Pictures) - Instructables
SNES Game Save Battery Replacement - Classic Console Discussion - AtariAge Forums
Replaced a NES Game Save Battery Too (SLIGHT MOD REQUIRED) -- ZELDA : r/gamecollecting
How To Change An NES Game-Save Battery - RetroGaming with Racketboy
SNES battery replacement for games that won't save - Howchoo
How to Replace an SNES Cartridge's Save Game Battery
Video: Replacing the battery of a SNES game, or; Can I (Still) Solder?
Game Boy Cartridge Battery Replacement - iFixit Repair Guide
Game Save Battery Install Service SNES NES SEGA GameBoy – RetroFixes
NES battery replacement for games that stopped saving - Howchoo