GBA 16MB, 64K EEPROM, Solar+RTC Flash Cart


This re-programmable Flash Cartridge allows you to play GBA games that use a solar sensor such as Boktai with EEPROM and RTC! Experience the authentic way of playing solar sensor games and because we use a photodiode which is sensitive to light, you can choose to either play indoors or outdoors – just calibrate the solar sensor to your environment. You will need GBxCart RW to re-write this flash cart.

30 July 2020 – Out of stock on batteries, expecting more in 3-4 weeks but you can order a cart without a battery and solder your own.

Check the list of games we have tested below and any game without saves will work. Since it’s just a regular cart, you can power off your system right after saving.

Questions? Jump on our Discord server where we and other users can help you or contact us via Twitter.

This cart should work on every system that supports GBA carts – GBA, GBA SP, GB Micro, DS, DS Lite and the Game Boy Player. This cart uses 5-10mA more compared to a regular cart. If you would like us to test a game, check the Game saves tested list below.

Comes in a generic GBA cartridge (various colours available) with no label. The board won’t fit in a genuine cartridge. Each unit is assembled in house and is tested on a Gameboy Advance. You can supply the ROM file for us to flash the cart if you like, it will be tested for 20-30 seconds to ensure it works and we will also testing saving too.

DHL users: We are able to send this cartridge with the battery installed, only a maximum of 2 cartridges can be sent with the battery pre-installed.

SKU: N/A Category:


Battery: CR1220 (should last 2-3 years). If you wish you can replace it with a larger battery (insulate it from the other components)

The maximum game size is 16MB as the way to access the EEPROM is to address higher than 16MB.

The PCB finish is ENIG, Gold fingers (on the edge connector) with a 45 degree bevel to give the maximum life for insertion/removal of the cartridge.

When you place an order, if you would like the flash cart to be programmed with a ROM, you need to supply it to us via email (you can reply to your order notification). It will be tested for 20-30 seconds on a Gameboy Advance to ensure it works, if it doesn’t work, we’ll contact you. If you don’t specify a ROM, it will be loaded with the “Graveblood Pre Pre Pre Alpha” Game Demo.

How to calibrate the Solar sensor
In games that support solar sensor calibration (remember to save afterwards to keep the calibration):
– Indoors (at night): Hold it about 2 metres away from a light source so that the solar gauge will only activate when close to the light source
– Outdoors: Cover the solar sensor with your hand as normal

EEPROM saving, Solar sensor and RTC in these games have been tested to work:

  • Boktai (USA/Europe)
  • Boktai 2 (USA/Europe)
  • Boktai 3 (Japan)
  • Boktai 3 (Japan with English translation hack, no solar patch required)

If your game isn’t here, send a quick email to with the ROM file and ask us to test it.

Demo of prototype cart

Additional information

Weight 11 g
Cart Colour

Clear Red, Clear Blue, Light Red, Clear Green, Green

EEPROM save chip

Yes, No I will solder my own


Yes (with battery pre-installed), Yes (without a battery), Not required

Pre-loaded ROM

I will provide a ROM to flash by email, Not required

Flash carts

GBA carts, RTC support, Saving supported


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