Discussion
4.1 Key findings
We found out that the lead-acid type of battery is affected by the temperature. The alkaline type of battery is not affected. Also we found out that only a mere 15 minutes in the fridge for lead-acid type battery affected the battery a lot as there was a significant drop in voltage (0.933V).
4.2 Explanation of key findings
Alkaline type of battery is not affected as the way they store their battery are not temperature sensitive. However lead-acid type of battery is temperature sensitive.
The results we collected shows that lead-acid type of batteries have significant changes to its voltage after being kept in -23°C, 8°C and 24°C environments for 15 minutes and let running a circuit of 2 similar motors for 24 hrs. However, the alkaline type of battery does not show significant changes to its voltage after being kept at -23°C, 8°C and 24°C for 15 minutes and let running a circuit of 2 similar motors for 24 hrs.
For the test where the batteries are kept at room temp and were let running for 24 hrs, the Eveready’s starting and end results are 3.417v and 2.484 respectively, whereas the Energizer’s starting and ending voltage for room temperature are 3.265 and 2.806.
As you can see, the voltage for Eveready dropped one whole volt while the Energizer batteries only dropped 0.4 volts.
4.3 Evaluation of hypothesis
Our hypothesis is the battery life of the batteries are affected by the temperature of the battery. The lower the temperature, the shorter the battery lifespan is then proven correct based on our results and evidence. A battery has two ends -- a positive terminal (cathode) and a negative terminal (anode). If you connect the two terminals with wire, a circuit is formed. Electrons will flow through the wire and a current of electricity is produced. Inside the battery, a reaction between chemicals take place. But the reaction takes place only if there is a flow of electrons. Batteries can be stored for a long time and still work because the chemical process doesn't start until the electrons flow from the negative to the positive terminals through a circuit.
4.4 Areas of improvement
We could loan more apparatus and finish the third experiment. We could have actually planned ahead of time, like say a week before the experiment weeks, so that we do not need to frantically squeeze in time and rush so that all is going along our as planned. We could have also ensured that all members of the team is doing their part by constantly checking on one another’s work progress and reporting to the teacher if one of us is not doing what he is required to do so that he is given a warning.
