ardfarkle Posted January 18, 2006 Share Posted January 18, 2006 (edited) llkylej wrote: The alkaline and nimh graphs have a different scale to them (alkaline y-axis is between 4 and 6.5, while nimh is between 4 and 6) and since, if i am reading the graph correctly, the nimh batteries completely drop below 4 volts after the graph passes ~1800, whereas every single alkaline is still well above 4 volts even up to 2600 for the rayovac. First off, only the voltages are important here. The 'number of samples' scale is nothing more than a time line to show that no long pauses existed during the testing procedure. The alkaline and NiMH tests used a different sample rate (alkaline=every 1 second, NiMH=every 6 seconds) hence the count discrepancy. 71 copies took ~170 minutes. If I had used a 1 second sample rate my DVM would have run out of sample memory. In addition, the sample towards the end of the test include failure information. This is why you see the voltage dropping below 4vdc on the NiMH chart. This information is normally edited out, but I left it there for an example that will made in the PD70X review. If you remove the error information and extrapolate the remaining values, you would have: Last successful copy and time per copy: Durcell - (((1842 samples * 1 seconds)) / 15 copies) = 123.33... seconds = 2.06 minutes per copy Energizer - (((1689 samples * 1 seconds)) / 15 copies) = 120.64 seconds = 2.01 minutes per copy Ray-O-Vac - (((2338 samples * 1 seconds)) / 19 copies) = 123.05 seconds = 2.05 minutes per copy Panasonic - (((1692 samples * 6 seconds)) / 71 copies) = 142.99 seconds = 2.38 minutes per copy Keep in mind the primary purpose of the charts are to show various aspects of battery performance for my PD70X review. However, they also demonstrate the performance advantages of NiMH cells over alkaline cells in higher current applications which is relevant to this thread. i guess that means the graphs were entirely meaningless ... Not at all. They show that empirical testing was performed. It's one thing to mention how long your alkaline cells lasted last month while eating a cheeseburger, and later while at the beach with your kids you noticed the NiMH cells didn't last as long. There are too many distractions and variables to take casual testing at face value. It all depends on the tester and test conditions. By using empirical testing techniques under controlled/repeatable conditions, such variables are laid to rest. In other words, these charts show I tested and documented what I am claiming. Edited January 18, 2006 by ardfarkle Quote Link to comment
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