A CR2025 or CR2032 battery with pre-soldered tabs
A 3.8mm security bit (Gamebit) screwdriver
A small Phillips screwdriver
A soldering iron (basic is fine)
Solder
Tweezers or pliers
(Optional) Electrical tape or Kapton tape
Make sure to work on a clean, static-free surface.
Use the 3.8mm security bit to remove the screw on the back of the Game Boy cartridge. Slide the shell down gently to open it. Be careful not to damage the plastic clips.
Inside the PCB, you'll find a coin cell battery (usually CR2025) soldered at two points. This battery keeps the save data and real-time clock alive.
Heat one contact point with the soldering iron while gently lifting the battery tab with tweezers. Repeat for the second contact. Remove the old battery once it’s loose. Be careful not to lift or damage the solder pads.
Place the new battery in the same orientation. Heat the solder pad and press the tab in place. Apply a small amount of solder to secure both contacts. Avoid using too much heat to prevent lifting the pad.
If using a battery holder (alternative method), install it first and then insert the battery.
Let the solder cool for a few seconds. Make sure the battery is firmly attached and doesn’t move. Optionally, apply tape for extra support. Close the cartridge by sliding the shell back into place and tightening the screw.
Insert the cartridge into your Game Boy and power it on. Start a new game, save, and turn it off. Turn it back on to confirm the save works. For Gold, Silver, and Crystal, check if the clock retains time correctly.
CR2032 batteries have slightly more capacity than CR2025 and are often compatible. Make sure there’s enough clearance inside the shell.
If you're not comfortable with soldering, you can look for pre-modded cartridges or contact a repair specialist.
Avoid touching soldering areas directly with your fingers. Always unplug your iron when done.
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