has anyone ever changed the batteris in a snes cart? i have a few that i fear need to be replaced but know nothing about it. what kind of battery does it take? is it the same battery for genesis carts? does it require soldering? i know nes carts require a certain kind of bit to remove the screws, is it the same for genesis cart? will save games be destroyed if they still exist. alot of questions but im just curious.