If anyone is interested, I found out the product is the Game Saver by Naki. They have one for SNES carts. It allows someone to power off a game, console, and TV at any point in the game and pick up where they left off previously. Precursor to save states, kind of. I dont know much about it beyond that.

The product I want is a Retrode, which allows one to pull save files off a cart and then put them back on, so you dont lose your progress when you change the battery. They come up on eBay now and then it looks like. They dont make them anymore