The materials required for this science fair project:
- 3 Energizer AA size batteries
- 3 Duracell AA size batteries
- 3 Eveready AA size batteries
- 6 plastic bags
- 6 rubber bands
- Battery holder
- 2 jumper wires with crocodile clips
- 1 AA battery- operated table fan
- 2 beakers
- 1 kg of dry ice
- 1 kg of ice cubes
- Safety goggles
- 1 pair of thick waterproof gloves to be used to handle the dry ice
- A clock to time the duration of the fan’s operation
1. For this science fair project, the independent variables are the type of the battery and the temperature conditions. The dependent variable is the time taken for the battery to run out of power while turning the fan motor. This is determined by keeping time with the clock. The constants (control variables) are the power of the fan motor, the size of the batteries and room humidity.
2. The performance of the batteries will be tested at the following temperatures: -78°C using dry ice, 0°C using ice cubes and 24°C at room temperature.
3. For the 1st test, an Energizer battery is placed in the battery holder, and 2 jumper wires with crocodile clips are connected to the holder. The battery and the holder are placed in a plastic bag with the other end of the jumper wires sticking out of the bag. The plastic bag is tied with the rubber band.
4. The plastic bag with the battery is placed in a beaker. Wear the gloves and transfer the dry ice to the beaker. Remember not to let the dry ice come into contact with your bare skin. Wear safety goggles at all times. Allow about 15 minutes for the temperature of the battery to stabilize in the beaker. The fan is then connected to the 2 wires sticking out of the plastic bag. Once the fan turns, the clock is started. With the help of an assistant, the time taken for the battery to drain and the fan to stop is recorded in the table given below.
5. Procedures 3 and 4 are repeated using the Duracell and Eveready batteries.
6. Procedures 3, 4 and 5 are repeated by using ice cubes instead of dry ice.
7. Procedures 3, 4 and 5 are repeated at room temperature without any cooling needed.
8. All the measurements recorded in the table given below.