I have a Nintendo GameBoy Color with some games that support saving your game status and also have a real-time clock, like Pokémon Red and Pokémon Silver.

But recently the game does not save any more, the saved position is reset. Also the real-time clock stopped and time only goes one while the game is running instead of 24/7.

How do such old Nintendo GameBoy games store save files, what could cause this sudden failure and how could I fix this?

2 Answers 2


Gameboy games use a CR2025 battery which over the years eventually dies stopping games from saving and causing previously saved games to disappear. Note however while the game is powered you can still save, however once you power down the save will be gone.

Original battery

In order to replace the battery you must open up the cartridge with a 3.8mm screwdriver security bit. Next you have to carefully pry the connectors loose from the existing battery since the original battery is actually soldered to the connectors. A common method on replacing the battery is to use an adhesive (preferably) electrical tape to hold the new battery in place. It's important to note you do not want to remove or break the current connectors, if you do so you will need to buy a complete kit which requires you to solder new connectors in place.

Replaced Battery

Once replaced you can continue to save games again, however down the road in 10-20 years you will have to replace the battery again.

To avoid losing your saves forever there are some great resources on actually transferring your existing saves to your PC.

  • 6
    Some gamecarts use the CR2032 battery, which have a larger capacity than the CR2025.The CR2032 can hold up to 210 mAh while the CR2025 only holds 160 mAh.
    – nabulator
    Commented Jan 17, 2017 at 21:13
  • 1
    Tape seems a bit unreliable. I would get a battery with leads pre-attached (easily obtained from digikey or ebay) and solder new leads in. Or even look at soldering in a low-profile battery holder, as that would make future replacements very easy. The battery, incidentally, is not soldered to the connectors; soldering to a battery is a very bad idea as it requires heating the battery well beyond the point of damage. Instead, it's tack-welded; you can get a machine for tack-welding batteries for a few hundred bucks, but for this application I would just get a battery with leads already on.
    – Hearth
    Commented Sep 11, 2022 at 17:52
  • @Hearth I agree actually, have done it quite a few times in the last few years.. keep in mind this answer is from 2016, I can't recall if they were doing preattached leads at that time. However I should probably update the answer.
    – Loktar
    Commented Sep 11, 2022 at 18:54
  • 1
    @Loktar They were; I've repaired a few gameboy and NES games this way going back several years. The tape method is probably the best option if you aren't comfortable using a soldering iron, though (although a soldering iron is really not difficult to use, not for something like this. As much as I hate them, you could probably do this with a $5 hardware store iron.)
    – Hearth
    Commented Sep 11, 2022 at 19:20
  • @nabulator sorry for that last comment I meant CR2025 holds 170 mAh Commented Sep 30, 2022 at 10:35

Gameboy games use CR2025 battery, which will die and take all the data with it:

It's lost for good. Saved games back in those days were preserved through the use of a battery right in the game pack, not stored on the gaming device itself like it is today. And when that battery dies, so does the saves with it. It's not about corruption of the save or whatnot, there just simply isn't a charge to hold that save data between sessions.

So you will need to get a new battery to keep on playing but your previous saved data is lost forever, as it is gone when the life of the battery is gone. You can replace the battery using the instructions of this site then your Gameboy should be properly working brand-new... literally.

But you can also try this site to store the data and prevent from being lost due to battery death.

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