Discussion

These are our key findings:-

Battery Discharge Rate [From Fig 1.1]

Panasonic: From the information gathered, the Panasonic battery’s voltage decreases at an average of 0.295V per half hour. 
Duracell: From the information gathered, the Duracell battery’s voltage decreases at an average of 0.3V per half hour.
Sony: From the information gathered, the Sony battery’s voltage decreases at an average of 0.294V per half hour.
Energiser: From the information gathered, the Energiser battery’s voltage decreases at an average of 0.294V per half hour.

Comparison of Battery Drainage [From Fig 1.2]

From the graph, although Sony and Energizer’s average rate of discharge may be lower than Duracell, they are the worst in terms of battery life compared to the other two batteries, Panasonic and Duracell.
Hence, we conclude that Panasonic is the best brand of battery in terms of being the most effective.

Our conclusion proves our hypothesis of Sony being the best brand of battery wrong. 

There are at least four experiments that have been conducted by others which are similar to our experiment-
http://www.energyquest.ca.gov/projects/battery.html, 
http://www.education.com/science-fair/article/battery-life-science-experiment/,  
http://www.sciencebuddies.org/science-fair-projects/project_sample_final_report.pdf, 
http://www.selah.k12.wa.us/soar/sciproj2004/NathanielH.html

These are the citations for the 4 websites respectively:-
Which Battery Lasts the Longest? (n.d.). Retrieved September 6, 2014.
Science Projects - Battery Life. (n.d.). Retrieved September 6, 2014.
(n.d.). Retrieved September 6, 2014.
Science Project 2004. (n.d.). Retrieved September 6, 2014.


Although all four of them did not completely use the same brands or the same battery types [for example, one of the experiments used AA batteries] as us to compare the effectiveness of the batteries, some of the experiments used similar techniques to arrive at their conclusion.