Relationship between cycle charge and discharge and life

Lithium battery life problem: Is the cycle charge and discharge once less life? Before answering this question, let us first talk about the test conditions of lithium battery cycle life.

The cycle is the use, we are using the battery, the concern is the time of use, in order to measure how long the rechargeable battery can be used for such a performance, the definition of the number of cycles is specified. The actual user usage is ever-changing, because the tests with different conditions are not comparable, and the comparison must be standardized to define the cycle life.

National standard for lithium battery cycle life test conditions and requirements: at an ambient temperature of 20 ° C ± 5 ° C, 1 C charging, when the battery terminal voltage reaches the charging limit voltage 4.2V, changed to constant voltage charging, until the charging current is less than Or equal to 1/20C, stop charging, set aside for 0.5h~1h, then discharge with 1C current to the end voltage of 2.75V. After the end of discharge, leave 0.5h~1h, and then proceed to the next charge and discharge cycle until two consecutive discharge times If it is less than 36 minutes, the end of life is considered to be more than 300 times.

Interpretation of the national standard:

A. This definition stipulates that the test of cycle life is carried out in deep charge and deep release mode.

B. The cycle life of the lithium battery is specified. According to this mode, the capacity is still more than 60% after ≥300 cycles.

However, the number of cycles obtained by different circulation systems is quite different, such as the other conditions above.

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