How long will save data last in a cartridge?

I was wondering, don't old cartridges use battery backed ram to keep save data? Well if thats the case eventually all those batteries are going to start to die and we'll lose all that save data.

its variable. one game dies after a year and others die in 20

Fire emblem sacred stones on the GBA died on me after 10 months. thats why i have 10 copys of the same game

Fire emblem sacred stones on the GBA died on me after 10 months. thats why i have 10 copys of the same game

hiphopballer

I think it depends on the usagebecause I still have some NES and SNES games withthe backup batteries still workin