Do the batteries in actual game cartridges used for in-game saving last forever?

I just thought of this question because of a reply of loony to one of the threads in the introductions section.Say you were lucky enough to find a Legend of Zelda (the first one on the NES) Cartridge in what looks to be in good working condition at some flea market or garage sale. And say you were also fortunate enough to get yourself a NES console too. Now comes my question.With almost thirty years from its release, would the Zelda Cartridge's save battery still work meaning playing it on an actual NES hardware for optimum "fun & recollection of childhood days" be worth it? Or should you just rely on an emulator since the battery may have been dead for some time now?

no, they don't last forever. It's not impossible to replace them though. My SNES games with battery saves are still functioning.

I haven't opened a cartridge with a save battery before, but am curious do the batteries look like those flat round batteres clocks, watches & motherboards use?Also, things like the Playstation memory cards, do they also use batteries of some kind? I have a bootleg PSOne memory card (there's alot of these here in Asia) that has a transparent body so I can see the circuitry & all I see are the green circuit board & a kind of chip in the middle but no visible battery.

A NES cartridge battery life in my knowledge could last from 10-15 years. You could change the battery yourself it's pretty easy and you can find tons of tutorials on the web I think. The cartridge is powered by a single CR2032 button cell type battery, the one used in wristwatches.

Well if they use those kinds of batteries then I guess you can bring a cartridge whose battery has run dry to a clocksmith since they know how to install those small batteries in wrist watches, cool :)

actually the cr2032s are a lot bigger than watch batteries. they're used on computer motherboards for maintaining the clock and cmos settings.

2032 is also called coin batteries for their size. Yes it's seen commonly on cmos but big watches ( especially the electronic ones) uses 2032.