Temperature performance batteries during discharge

The capacity test of a traction battery is performed not only for quality assurance, but also to evaluate the endurance of the battery during operation. The capacity test is the only way to get a view of the electrical power of a battery. The test is described in EN 60 451, Part 1, as a discharge with a constant current I5 (A), compensation of the temperature by 0.6% per degree if the electrolyte temperature differs from 30 °C. To execute a test qualified testing equipment and educated staff are needed. 

The studied BCAP0350 DLC has a D-cell battery shape factor which is defined in the standard with a 33 mm outside diameter and a 61.5mm length. The total external surface is about 80cm2. The production of losses inside the DLC is assumed to be uniform in the volume. In the case of a 30 A charge/discharge current the dissipated power is equal to 2.88 W. The measurements have been performed at room temperature 7 = 20°C which was constant during the experiment. The DLC is only cooled with a slowly moving airflow due to the natural convection. 

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