Some guy left his Super Nintendo on for 20 years to save his progress in a video game.
That's really the case here. That is exactly why a Japanese gamer kept his SNES plugged in and powered on — with very rare, emergency exceptions — over the past two decades.
Super Nintendo cartridges, as you have correctly noted to yourselves already, have the means of preserving gamesaves (so did NES cartridges, but that's beside the point here).
The problem is some did so with the help of a battery inside the cartridge, and batteries die. That's what happened inside Twitter user Wanikun's copy of Umihara Kawase, a Japan-only release from 1994. Wanikun tweeted about it back in September but it was noticed by several gaming publications this week.
Wanikun would not accept that these memories of the life he led in this video game would be lost in time, like tears in rain. So he kept the game plugged into his Super Famicom (as it was called in Japan) to preserve his game save. He estimated that his console was kept in operation for more than 180,000 hours. (That was back in September, by the way.)
Once the console was unplugged — in the last stage of moving his home. Wanikun was able to get the SNES powered back on in time to keep the game save going.
That's dedication. Modern consoles like the Xbox One and PlayStation 4 have background modes that, technically, keep them powered on for days and months on end but still, 20 freaking years for a 16-bit console is a bit extreme.
I checked my Xbox 360 for the oldest gamesave I have, and I think it goes back to Bionic Commando: Rearmed in 2008. The closest thing to this I've done is keep my NBA Elite 11 demo preserved — across three different consoles — because it was removed from Xbox Live quickly after the game was canceled more than five years ago. I was also given a friend's Xbox and it still had all of its gamesaves intact, some of which I preserved in tribute. I haven't powered on that console in maybe 18 months but it has some Hitman: Silent Assassin data going back to 2004.
What's the oldest gamesave you have? Note: the code for Super Macho Man in Mike Tyson's Punch-Out!! does not count, unless you still have it written down on a piece of notebook paper from 1988.