WTB Carts with dead back-up batteries

[Jibbajaba]

Looking for NES, SNES, or Genesis carts with dead back-up batteries in them. Need to be in good condition, and need to work aside from the battery back up issue.

Thanks,

Chris

EDIT: should have been more specific about this. I am just interested in commons right now, and no sports games. I want to play around with installing coin battery holders in the carts instead of the way they come installed from the factory, but I don't really want sports game because it isn't really worth it to extend their lives.