Why Your Old Cartridge Lost Its Save (Save Batteries Explained)

By s-coding23 · October 30, 2026 · 7 min read

You blow the dust off an old cartridge, switch it on, and your save from decades ago is gone. Or worse, you start a new game, play for an evening, and it vanishes the moment you turn the console off. Both have the same cause: the little battery inside the cartridge has run out.

How old cartridges saved your game

Many cartridges from the 1980s and 1990s stored saves in a type of memory called SRAM. It's fast and cheap, but it forgets everything the instant it loses power. To keep your save while the console was off, manufacturers put a small coin-cell battery inside the cartridge, usually a CR2025 or CR2032, the same size you'd find in a watch or a car key.

Those batteries were rated for many years, and many lasted far longer than anyone expected. But they've now been running for 25 to 35 years, and a lot of them are finally empty.

Which games are affected?

Any cartridge that saves with SRAM and a battery. Some well-known examples:

• Pokemon Red and Blue on the Game Boy.
• Pokemon Gold, Silver and Crystal, which also run a real-time clock from the same battery, so they tend to drain it sooner. A clock error message at start-up is often the first sign.
• The Legend of Zelda: A Link to the Past, Super Mario World and many other Super Nintendo games with save files.
• Ocarina of Time on the Nintendo 64.

Plenty of games never needed a battery. Many Nintendo 64 games, including Super Mario 64, saved to EEPROM, which keeps data without power. PlayStation games saved to memory cards using flash memory. Many Game Boy Advance games saved to flash or EEPROM too.

The Game Boy Advance Pokemon clock

Pokemon Ruby, Sapphire and Emerald save your game to flash memory, so your progress is safe even with a dead battery. Their battery only runs the clock. When it dies, the game shows a message that the internal battery has run dry, and time-based events such as berry growth stop working, but you can still save and play.

How to tell if the battery is dying

• The game won't keep a new save after you switch off.
• An old save is missing or corrupted.
• Games with clocks show a clock or time error.

Protect your save first

If your old save is still there, back it up before you do anything else. Removing the battery erases SRAM instantly. Cartridge readers that plug into a computer over USB can copy the save to a file, which you can then put back after a battery swap, or load into an emulator.

Replacing the battery

A battery swap is a common, cheap repair, but it does involve opening the cartridge and, for most of them, soldering:

1. Open the shell. Nintendo used security screws: Super Nintendo and Nintendo 64 cartridges need a 3.8mm security bit, and Game Boy and Game Boy Advance cartridges need a tri-wing screwdriver. Both are inexpensive.
2. Swap the battery. The original is soldered in with metal tabs. Replace it with a new tabbed battery of the same type, or fit a battery holder so the next change needs no soldering.
3. Restore your save from your backup, and test that a new save survives switching off.

If soldering isn't for you, many retro game shops and repair services will do it for a small fee.

Playing without the worry

Official re-releases on modern systems save to the console's own storage, and emulators save to a file on your computer that you can back up like any other. If keeping a 30-year-old save matters to you, back it up today rather than waiting for the battery to decide for you.