After months of cycling and data-logging at a National Renewable Energy Lab, the Ni-Fe battery tests are finally complete. I am now releasing the complete data set for peer review.
I invite you to download the battery test data, and discuss what you find. I will be happy to answer any questions about the tests.
Here are some important details to consider:
[LIST][*] The test was designed solely to verify battery capacity, not to test for efficiency.[*] 4 cells were tested: 200Ah, 300Ah, 600Ah, 700Ah Each cell has a nominal voltage of 1.2Vdc [*] We tested cells at 3 discharge rates (C/20, C/10, C/5) because these mirror real-life conditions more than the 100 hour rates.[*] We tested the cells at 3 different ambient temperatures (20C, 0C, -20C) [*] In every test, the cells were all charged at the C/5 rate for up to 7 hours.[*] Each test was repeated the times (three cycles) at each temperature and discharge rate[*] During the -20C temp testing, the refrigerator coils froze due to the amount of off-gassed H20 inside the chamber, resulting in a temperature rise. This gave a new twist on this data set because the temperature was not held constant.[/LIST]
Iron Edison at NREL_.jpg Iron Edison at NREL_2.jpg NREL Thermal Chambers.jpg NREL Battery Cyclers.jpg NREL -- Technology Assistance.jpg
I invite you to download the battery test data, and discuss what you find. I will be happy to answer any questions about the tests.
Here are some important details to consider:
[LIST][*] The test was designed solely to verify battery capacity, not to test for efficiency.[*] 4 cells were tested: 200Ah, 300Ah, 600Ah, 700Ah Each cell has a nominal voltage of 1.2Vdc [*] We tested cells at 3 discharge rates (C/20, C/10, C/5) because these mirror real-life conditions more than the 100 hour rates.[*] We tested the cells at 3 different ambient temperatures (20C, 0C, -20C) [*] In every test, the cells were all charged at the C/5 rate for up to 7 hours.[*] Each test was repeated the times (three cycles) at each temperature and discharge rate[*] During the -20C temp testing, the refrigerator coils froze due to the amount of off-gassed H20 inside the chamber, resulting in a temperature rise. This gave a new twist on this data set because the temperature was not held constant.[/LIST]
Iron Edison at NREL_.jpg Iron Edison at NREL_2.jpg NREL Thermal Chambers.jpg NREL Battery Cyclers.jpg NREL -- Technology Assistance.jpg
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