There are many factors that affect the cycle life of secondary batteries, such as electrode materials, electrolytes, membranes and manufacturing processes will have a greater impact on life. These factors affect each other, and jointly determine the battery life.
In the battery life test, the battery capacity is not the only measure of the battery cycle life index, should also consider its voltage characteristics, internal resistance changes. Batteries with good cycle performance, after a number of cycles, not only to capacity attenuation does not exceed the specified value, the voltage characteristics should also be no corresponding large attenuation.
Battery life test circuit and the capacity detection circuit is basically the same, but after the end of a cycle should be followed by another cycle until the end of the test until the end. Usually in a certain charge condition under the conditions of circulation, and then detect the battery capacity of the attenuation, when the discharge capacity of the initial capacity of about 70% (different batteries have different provisions), calculate the number of cycles, is the battery cycle life.