All of the Gen II games I've had still work luckily!
...
*looks around worriedly*
...
*Goes check Gold game*
...
Yeah, still works. I once was given a free Gen II game and I thought, "Wow! Aren't I lucky that somebody gave me a free Pokemon game!" Then when I realized it wouldn't save, I tricked a kid into giving me his working Pokemon Silver. I feel bad about it to this day, but he was a very gullible person. Here's what the conversation was:
Me: Hey you wanna trade me your Pokemon Silver for my Pokemon Gold?
Him: Why?
Me: Well, uh... Pokemon Gold is better than Silver.
Him: But I like this game.
Me: Uh, well this one is good for cheats!
Him:...
Me:...
Him:... Ok!
Yeah. I am glad that mine still works! Although it'll probably flop anyday now. They say once the time slows down in game, it is a sure sign. Mine is 5 minutes slow so far...
But it should be good for now. Enjoy it while you can!