Science Fair Projects on Battery Electrical Output

Tips for Battery Science Fair Projects

The electrical output of a battery is going to be dependent on several factors. When developing a battery experiment you need to make sure you isolate one factor at a time. Otherwise you will not know what factor is impacting the electrical output of the battery.

PURPOSE

The purpose of phase one of this experiment was to measure the electrical output of a hydrogen fuel cell at different load levels.

The purpose of phase two was to measure the electrical output of both Nickel-Cadmium and Nickel-Metal Hydride rechargeable batteries at different load levels.

The purpose of phase three was to compare the electrical output of a hydrogen fuel cell with the rechargeable batteries at different load levels.

I originally became interested in this area last year when I was reading a newspaper article saying that auto manufacturers might start making cars operated by fuel cells. That lead me to conduct a study to see if the electrical output of a fuel cell changed when operated at different temperatures. Following that series of experiments I became interested in fuel cell output under low and high load levels. At about the same time my brother was complaining about his rechargeable batteries not powering an electrical toy long enough. I decided to compare the fuel cell with rechargeable batteries.

The information gained from this experiment could help consumers decide which rechargeable battery to purchase. It could also help manufacturers decide whether a fuel cell would be preferable to rechargeable batteries for a given load.

Solar House	Fuel Cell Car	Knight Invader III Car	OWI Turbo 3000 car
Ages 12 thru High School	Ages 12 thru High School	Ages 9 and up	Ages 9 and up

HYPOTHESIS

My first hypothesis was that the fuel cell would produce more electrical output as the load decreases. I based this on Mrs. Theresa Koehler, an employee for Pacific Northwest Laboratories, who told me via e-mail that fuel cells produce more electricity at higher load levels.

My second hypothesis was that the rechargeable batteries would produce more electrical output as the load decreased. I based this on an email from Mrs. Theresa Koehler, who told me that batteries can respond faster than fuel cells.

My third hypothesis was that fuel cells would have an overall greater electrical output than the rechargeable batteries. I based this also on a graph sent by Mrs. Koehler showing that fuel cells have a higher wattage per kilogram.

My fourth hypothesis was that the NI-MH rechargeable batteries would have an overall greater electrical output than NI-CAD rechargeable batteries.
I based this on a graph from Mrs. Koehler that showed this with wattage compared to kilowatt hours.

EXPERIMENT DESIGN

The constants in this study were:
* The test group size
* The batteries
* The fuel cell
* device to recharge the batteries and the fuel cell
* The room that the experiment takes place
* The temperature that the experiment is conducted
* The type of battery
* The type of fuel cell
* The type of fuel used in the fuel cell

The first manipulated variable was the amount of electrical load that the fuel cell powered.

The second manipulated variable was the type of rechargeable battery.

The third manipulated variable was the amount of electrical load that the rechargeable batteries powered.

The responding variable was the electrical output of the fuel cell and the rechargeable batteries.

To measure the responding variable I will use a computerized voltage probe made by Vernier Company and Logger Pro 3.0 software

MATERIALS

PROCEDURES

PREPARTION PHASE
1. Assemble the board
a. Screw the battery holder to one end of the board.
b. Put two wire leads to the ends of the holder.
c. Screw the knife switch onto the board and then attach the leads to the switch.
d. Put two wire leads on the other end of the knife switch.
e. Attach a Thamas Komos multimeter (set to 200ma) to one lead.
f. Attach the terminal strips to the board opposite of each other.
g. Attach the other metal probe on the multimeter to one of the terminal strips.
h. Attach the light bulb holders in a row at the end of the board.
i. Put the correct light bulbs into the holders.
j. Put 4 pieces of wire onto both terminal strips.
k. Attach alligator clips on to all 8 pieces of wire.
2. Set up the logger pro and Vernier volt probe
a. Install Logger Pro 3 into a strong computer.
b. Set the time to 2 hours and record 60 times an hour
c. Put in the desired battery and number of light bulbs.
d. Attach the probe to the computer and to channel 1.

I. Phase 1: Fuel Cell
1. Get the fuel cell ready.
a. Take off the protector tubes on the side.
b. Use the syringe to pump water through the side of the cell.
c. Stop when you put one ml of water into the cell.
d. Put 47 ml of water into the container that holds the gas containers. Shine a lamp straight onto the middle of the solar panel, with the panel flat, to break the water a part until the gas containers have gas bubbles coming out of the top.
2. Do test one with load of 1 small flash light bulb
a. Start the collecting. Use a multimeter to measure the amperage.
b. Conduct trial two. Use the same directions above (1a - 1d and 2a)
c. Conduct trial three. Repeat step 2b.
d. Conduct trial four. Repeat step 2b.
3. Do test with load of 2 small flashlight bulbs
a. Repeat steps 1a-2c.

II. Phase 2: NI-CAD
1. Do test one with 1 flash light bulb
a. Start the stopwatch. Use a multimeter to measure the output of the cell every minute. Stop when the battery runs out of energy.
b. Conduct another trial. Use the same directions above.
c. Charge the battery for seven hours.
d. Conduct the final two trials of this load.
2. Do test two with 2 flash light bulb
a. Repeat steps 1a-1d.

III. Phase 3: Ni-HM
1. Do test one with 1 flash light bulb
a. Start the stopwatch. Use a multimeter to measure the amperage
b. Conduct another trial. Use the same directions above
c. Charge the battery for seven hours.
d. Conduct another trial. Use the same directions above
e. Conduct another trial. Use the same directions above
2. Do test two with 2 flashlight bulb
a. Repeat steps 2a-2e.

RESULTS

The purpose of phase one of this experiment was to measure the electrical output of a hydrogen fuel cell at different load levels.

The purpose of phase two was to measure the electrical output of both Nickel-Cadmium and Nickel-Metal Hydride rechargeable batteries at different load levels.

The purpose of phase three was to compare the electrical output of a hydrogen fuel cell with the rechargeable batteries at different load levels.

The results of the experiment were that the Ni-HM batteries performed the best. They held an almost constant voltage throughout the 2 hour test. The fuel cell did the worst staying at about zero for the majority of the two hours. All of the batteries and the fuel cell did the best at lower load levels

CONCLUSION

My hypothesis was that the fuel cell would produce more electrical output as the load decreases. The results indicate that this hypothesis should be accepted.

My second hypothesis was that the rechargeable batteries produce more electrical output as the load decreased. The results indicate that this hypothesis should be accepted.

My third hypothesis was that fuel cells would have an overall greater electrical output than the rechargeable batteries. The results indicate that this hypothesis should be rejected.

My fourth hypothesis was that the NI-MH rechargeable batteries would have an overall greater electrical output than NI-CAD rechargeable batteries. The results indicate that this hypothesis should be accepted.

Because of the results of this experiment, I wonder if the fuel cell would perform the same if I used regular drinking water in the fuel cell instead of distilled water. I also wonder if the amount of time I charged the fuel cell and the batteries affect the experiment. I also wonder what would happen if I used different brands of batteries. I especially wonder if using a bigger fuel cell would have made the experiment a better comparison test.

If I were to conduct this project again I would conduct more trials. I might also try 2 more load levels. I could also record data for more than 2 hours. I might try 5 hours. I would also record data points less frequently so that my graphs would be easier to read.