Lithium battery charging cycle and battery life relationship

Lithium battery charging cycle has a close relationship with lithium battery life. A charging cycle refers to a complete charging and discharging process of a lithium battery. If it is decomposed, a charging cycle consists of a full charge and a full discharge process. The life of a lithium battery is related to the number of completions of its charging cycle, and has nothing to do with the number of times the lithium battery is charged or discharged.

In other words, the lithium battery charge cycle is an expression of the lithium battery charge, which means that the battery power is from full to empty and then empty to full. From the voltage point of view of the existing battery design, a single lithium battery is used from an empty load of 4.2V (capacity is nominal capacity) to 2.75V (at this time, the capacity is zero) and then an opposite process is completed charging cycle. In this process, if the battery starts to charge at a certain voltage between 4.2V and 2.75V, it cannot be counted as a charging cycle. From a capacity point of view, if the 2200mAh lithium battery starts to charge when it has a capacity of 1100mAh, it cannot be counted as a charging cycle, but only counts as a half cycle. However, in this way, the number of times the lithium battery is charged and discharged (the charging cycle is 500 times) reaches 1000 times.

It is further understood that, in terms of numerical value, a charging cycle of a lithium battery is equal to the total electrical power that can be output by a fully charged lithium battery, and still takes a nominal new lithium battery of 2200 mAh as an example, and its output power is 8.14 wh, that is, Said, fully charged battery is enough to work at 2200mA for one hour, which is the meaning of full charge and discharge.

The lithium battery charging cycle currently designed can generally reach 500 times, which is the life of the lithium battery. The IEC standard stipulates that after 500 cycles of lithium batteries, the charge should be 60%.

Here, to correct the consumer's "can charge more than 1000 times" propaganda as a measure of the life expectancy of lithium battery fault, as mentioned above, a charging behavior may complete a charging cycle, but there may be only half a charge Cycles, some lithium battery manufacturers may mislead consumers by making such instructions with imprecise parameters for the purpose of promoting battery performance. In fact, the principle that a lithium battery can be counted as a charging cycle in terms of capacity from zero to nominal capacity and then from nominal capacity to zero capacity has not changed. Therefore, the life of a lithium battery can be improved by a certain method, but always based on the charging cycle, which makes the improvement in life limited to a limited range.

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