I'd like to know more about the batteries that are used for video games. Can anyone tell me any good information or good web sites?

Basicaly, I'd just like to know what kind of batteries have been used in carts over the years, how they actually work to save data, and how reliable they are, as well if replacements can be found.

I remember Nintendo saying with the NES in the late 80's that batteries would last about 10 years. I guess that's all they figured someone would play the games for. This seems confirmed when I helped a friend hook up a NES he got at a yard sale a couple years ago and almost none of the games with batteries would hold a save.

What about the Internal RAM's that are used in some systems like the 3DO and the Sega CD? I know those can go bad also, but are those batteries as well? How can you replace those?

The only carts still in production that use batteries now a days, I guess, would be the GBA games. How long are THOSE batteries good for?