Electro-Chem-Technic

Mini Fuel Cell - Instructions, Simpler Version

Although designed for classroom use, the Mini Fuel Cell can be used in more informal settings, such as at home, scout groups, science fairs etc.

Apart from the Mini Fuel Cell and the fuel - both of which can be obtained from us - the only other things you need are:-

  • water - ordinary tap water will do fine.
  • caustic soda (sodium hydroxide) - which can be bought from hardware stores, which sell it as drain cleaner.
  • some small electrical device for the fuel cell to power, such as an electric motor. For best results sodium borohydride - which we sell - should be used as the fuel. However, any methanol or ethanol containing liquid such as methylated spirits, windshield washer fluid, alcoholic drinks, etc. will give enough current to drive a small motor.

    Step by step instructions

    1. First, put one teaspoon of caustic soda into the anode beaker of the fuel cell.

    2. Then add a "pinch", about 20 grains, of the sodium borohydride fuel.

    3. Now add water till it reaches the fill line - about 80 mL. Gently swirl the mixture to dissolve the crystals. The water will become slightly warm - this is not a problem. With new cells the liwuid will also darken a little as carbon is washed out of the electrode - again, no problem. This liquid, called the ELECTROLYTE, is corrosive. Take car, it will damage furniture uf you spill it, and irritate skin. Wash any spills promptly with plenty of water.

    4. Now insert the red cathode into the cell.

    5. The cell is now ready and working. If you have a voltmeter you could measure its voltage. (About 0.9 V if using sodium borohydride, about 0.7 for alcohol.)

    6. Now connect something to the cell. Because fuel cells are high current/low voltage devices, one fuel cell on its own cannot do much. Small electric motors are about all you can use. However, if you use our DC/DC Converter, which boosts the voltage (and reduces the current) then more impressive things like radios and LEDs can be used, as below.

    Fuel Cell Powered Radio

    7. Once you have finished the electrolyte can be poured down the drain. After all, its only drain cleaner! The cell should be rinsed out with clean water. The electrodes should be gently padded dry with paper towel before the cell is packed away.

    If you want more details of the chemistry involved, click here for the more advanced version of the instructions.

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