Im opening and cleaning nes games today...just ran across a 5 screw metroid...does anyone know why theres a spot on the board for a cr 2025? Didnt know metroid ever had the option to save

It doesn't. It's just there probably because they had more of those on hand at the time. I know lots of games that have a place for battery that use a WRAM but no saving.

If you check Spot, Mule, Kid icarus (to name a few) same setup. No battery but spot for one. It just depends on the game.

Easier to design one board and just add the battery as needed than design a separate board. I assume this to be true based on the fact there's only like 21 SNROM games.

Wish it was the same setup with TSROM

So adding a battery would do nothing besides maybe break the game then?

For Metroid, possibly. For most it should be no. Metroid handles dirty RAM badly. Putting an SRAM there and backing it would mean if the right byte gets corrupted somehow, it'd be hard to get to not play glitchy and have effects on it.

For Metroid, possibly. For most it should be no. Metroid handles dirty RAM badly. Putting an SRAM there and backing it would mean if the right byte gets corrupted somehow, it'd be hard to get to not play glitchy and have effects on it.