Have the Game Boy Advance game Boktai: The Sun is in Your Hand! in the cartridge slot to get the "Solar Sensor Ver. 1" as an item in the "Valuables" menu. This Solar Sensor allows Aaron or Lucian to replenish their ENE at a faster rate based on sunlight and will charge the Solar Station.

Have the Game Boy Advance game Boktai 2: Solar Boy Django in the cartridge slot to get the "Solar Sensor Ver. 2" as an item in the "Valuables" menu. This Solar Sensor allows Aaron or Lucian to replenish their ENE and LIFE at a faster rate based on sunlight and will charge the Solar Station.

Have the Game Boy Advance game Shin Bokura no Taiyou: Gyakushuu no Sabata in the cartridge slot to get the "Solar Sensor Ver. 3" as an item in the "Valuables" menu. This Solar Sensor allows Aaron or Lucian to replenish their ENE and TRC at a faster rate based on sunlight and will charge the Solar Station.