2. Remove the stoppers from both the oxygen and hydrogen storage cylinders.

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1 Fuel Cell User Guide Introduction The information in this document provides instruction on the proper way to setup, charge, and use the Heliocentris Fuel Cells. It is recommended that this document be read carefully and completely before attempting to use the fuel cells. Following the proper directions will ensure that the fuel cell membrane is not damaged during use in the classroom. The Parts of the Heliocentris Fuel Cell 1. Water reservoir Hydrogen side 2. Storage cylinder Hydrogen side 3. Hydrogen side stopper 4. Storage cylinder Oxygen side (hidden) 5. Banana jack negative terminal 6. Protective diode 7. Banana jack positive terminal 8. Water reservoir oxygen side Preparing the Fuel Cell for Use 1. Place the fuel cell upside down on a flat surface. In this placement the numbers will be upside down and the negative (black) terminal will be on top. 2. Remove the stoppers from both the oxygen and hydrogen storage cylinders. 3. With distilled water, fill both storage cylinders to the top of the small tubes in the center. a. Note: Failure to use any liquid other than distilled water will result in permanent damage to the proton exchange membrane (PEM). Principles Of Engineering Fuel Cell User Guide Page 1

2 4. Tap the fuel cell lightly. This causes water to flow into the area surrounding the proton exchange membrane (PEM). 5. Be sure to have towels nearby, because water will spill on the tables during this step. Add more water until it starts to overflow into the small tubes in the center. 6. Put the stoppers back onto the cylinders. Make sure no air bubbles larger than 0.5mL are trapped inside. 7. If the membrane has not been used in a while and is dried out, allow it to soak for about 10 minutes before attempting to charge the fuel cell. 8. Turn the fuel cell right side up. Powering the Fuel Cell (Electrolysis) Solar Panel as a Power Source 1. When powering the fuel cell, a solar panel in combination with a light source can be used as the power source. Using the sun as a power source is only recommended on a very sunny day. This may take significantly longer to produce enough hydrogen and oxygen to power the fuel cell. A good source of indoor light is a Watt Parabolic Aluminized Reflector (PAR) light bulb. Warning: Failure to follow guidelines regarding the light source could result in malfunction or permanent damage to the solar cells. Principles Of Engineering Fuel Cell User Guide Page 2

3 o Use light sources with a maximum power of 120W or less. o Keep the light source at least 8 inches away from the solar panel. o Do not concentrate the light with a reflector. 2. Connect the solar panel and the fuel cell as shown. The diagram below illustrates the necessary setup for separating hydrogen and oxygen in the fuel cell. The positive terminals on both the solar panel (1) and fuel cell (3) are connected by a conducting wire. The negative terminals on both the solar panel (2) and fuel cell (4) are connected by a conducting wire. 3. The formation of gas should begin immediately in both storage cylinders. 4. Once gas begins to bubble up from the small tube on the hydrogen side, the fuel cell is fully charged. The light source can be turned off at this time. For optimal performance, continue producing gas until the oxygen storage cylinder has also been completely filled. An endpoint is reached when gas begins to bubble up from the small tube on the oxygen side. Principles Of Engineering Fuel Cell User Guide Page 3

4 Alternative Power Sources Other power sources can be used to power the fuel cell, but this should be done with caution. Failure to power the fuel cell according to the following guidelines will result in permanent damage to the PEM. Over time, the fuel cell may lose its functionality. Do not allow currents more than 500 ma to flow through the fuel cell. Electrical connections are the same as when using a solar panel. Connect the positive terminal of the power source to the positive terminal of the fuel cell with a conducting wire. Connect the negative terminal of the power source to the negative terminal of the fuel cell with a conducting wire. Examples of Alternative Power Sources A current limiting DC power supply set to a maximum current below 500 ma and maximum voltage of 2 V. 1. Prior to connecting the fuel cell to the power supply, set the voltage limit to 2 V and the current limit to 0 A. 2. Connect the positive terminal of the power supply to the positive terminal of the fuel cell. Connect the negative terminal of the power supply to the negative terminal of the fuel cell. 3. Gradually increase the current limit until it reaches A, which is safely below the 0.5A threshold. Gas should be produced immediately. A different solar panel with the same current / voltage limits. Two solar panels connected in parallel, as long as the 500 ma current limit is not exceeded. Hand-crank generator, as long as the 500 ma current limit is not exceeded. Fuel Cell as a Power Source Failure to follow these warnings will result in irreversible deterioration of the PEM. DO NOT short circuit the fuel cell. This will result in irreversible deterioration of the PEM. A 10 Ω resistor in the circuit will prevent a short circuit. Do not allow current flowing out of the fuel cell to exceed 500 ma. Principles Of Engineering Fuel Cell User Guide Page 4

5 Fuel Cell Storage 1. Remove stoppers and pour out all remaining water. Storing the fuel cell with water in it will result in deterioration of the fuel cell. 2. Allow the fuel cell to dry completely. 3. To ensure that the PEM is allowed to dry fully, do not replace the stoppers prior to storage. 4. Store the components at temperatures between C (50 95 F). Principles Of Engineering Fuel Cell User Guide Page 5

6 Specifications Solar Panel Characteristics Operating Temperature Length / width / height Weight With incident power of 1000 W/m2 at 25 C (77 F): Open circuit voltage Short circuit current Operating current Operating voltage Value C ( F) 52 mm 70 mm 130 mm (2.04" 2.8" 5.11 ) 60 g 2.8 V 250 ma 200 ma (with 10 Ω load) V Fuel Cell Characteristics Length / width / height Weight (unfilled) Operating temperature Storage temperature Gas storage Electrolyzer operation Working voltage Current Rate of hydrogen production, maximum Fuel cell operation Operating voltage Operating current Operating power Value 70 mm 90 mm 80 mm (2.75" 3.54" 3.14 ) 140 g (2.1 oz) C ( F) 5 40 C ( F) 2 15 ml V ma 3.5 ml / min V 500 ma 250 mw Principles Of Engineering Fuel Cell User Guide Page 6