This is a (frequently updated) lot of Japanese Game Boy games which I have replaced the batteries for. Game Boy batteries die more often than with other systems, especially with some of the Pocket Monsters (Pokemon) games, so if you want one of the Pocket Monsters games that are prone to dying, buy from me! I solder in new batteries, testing each one first with a multimeter and if feasible by playing the game briefly and seeing if it holds a save.  All games have their contacts cleaned and have been tested to start reliably. The battery used is a CR2025, which should last longer than the smaller batteries that come standard in a Game Boy cartridge. All batteries are soldered in securely; there are no shortcuts taken, if a job is going to be done it should be done in the best way possible!

As I come across suitable games they will be added to this list, so check back once in a while! There are discounts for multiple purchases, and all items may be returned for free within 30 days (although this should not be necessary!)