Replacing vintage game batteries is a must.  Not only will this restore the save function but will preserve your game. When game batteries age they will eventually leak on the motherboard and cause damage.

Item Condition: 100% Brand new and high quality
Volts:  3V, Non- rechargeable
Size: 16mm x 1.6mm

Batteries are easy to replace if you have soldering skills. This CR1616 is the exact size of battery used in some original GameBoy games. Many installation tutorials can be found online

Open your game & confirm battery size before ordering.

Tools needed for most games:

3.8mm or 4.5mm Game Bit (sold in my store)

Solder and Iron

Note: This install is easy but requires soldering skills.