Direct methanol fuel cell system using solid methanol, portable electronic device using same, and fuel cartridge for direct methanol fuel cell system

A direct methanol fuel cell system, comprising:

• a fuel cartridge having an elongated-box shape with flat surfaces and an interior storing solid methanol;
• a fuel cell unit having two configurations including an open configuration having a hollow interior and a closed configuration containing the fuel cartridge therein, the fuel cell unit having an elongated-box shape with flat wall portions adjacent the flat surfaces of the fuel cartridge when the fuel cell unit is in the closed position, and
• fuel cells being respectively disposed at the flat wall portions of the fuel cell unit and opposite to the flat surfaces of the fuel cartridge when the fuel cell unit is in the closed configuration,
• wherein the fuel cartridge includes apertures on the flat faces thereof, the apertures are configured to close when the fuel cartridge is outside the fuel cell unit, and the apertures are configured to open and permit passage of methanol from the fuel cartridge to the fuel cell when the fuel cell unit is in the closed configuration containing the fuel cartridge therein.