Does fast charging affect Li-polymer battery life?
Does fast charging affect battery life
In principle, the damage to the Lipo battery basically comes from two sources.
On the one hand, when the Li-polymer battery is charged and discharged, the cathode and anode of the Lithium battery will shrink and expand with the release and absorption of ions, and a long time fast charging will damage the chemicals on the battery, resulting in shorter battery life.
On the other hand, when fast charging, due to the relatively high current, the thermal effect of the current will intensify, resulting in high-temperature battery, high temperature will also make the capacity plummet and the phenomenon of permanent damage to the battery cell.
As we all know, one of the advantages of lithium batteries is that you can charge the lithium-ion battery at any time at a convenient moment, without having to think about charging after the electricity is used up. So, what do you mean by a charging cycle
A charge cycle means that all the power of the battery is from full to empty, and then from empty to full process, which is not the same as charging a single charge. To put it simply, 600 mA lithium battery, you first charged from 0 mA to 400 mA, with ah with N mA; then you charged 150 mA, then with N mA; finally charged 100 mA, when the last charge to 50 mA, this battery a charging cycle is up. (400+150+50=600)
A lithium battery in the first day only half of the power, and then fully charged for it. If it is still so on the second day, i.e., it is charged when half is used, the total of two charges down, this can only be counted as one charge cycle, not two. Therefore, it may usually take several charges to complete a cycle. Each time a charge cycle is completed, the power will decrease a little. This is why many people who use Li-ion phones often say, "This stupid phone, which could last 4 days when I first bought it, can now only last 3.5 days on a single charge. However, this power reduction is very small, high-quality batteries will still retain 80% of the original power after multiple cycles of charging, many lithium-powered products are still used as usual after two or three years. Of course, lithium battery life to the end or needs to be replaced.
The life of a lithium battery is generally 300-500 charge cycles. Assuming that a complete discharge provides 1Q of power, if we do not consider the reduction of power after each charge cycle, the lithium battery can provide or replenish a total of 300Q-500Q of power during its life. From this we know that if it is charged with 1/2 at a time, it can be charged 600-1000 times; if it is charged with 1/3 at a time, it can be charged 900-1500 times. And so on, if the charge is random, the number of times is variable. In short, no matter how to charge, the total replenishment into 300Q-500Q of power is constant. Therefore, we can also understand that: the life of lithium batteries and the total charge power of the battery, and the number of times to charge have nothing to do with it. Deep discharge deep charge and shallow discharge shallow charge for lithium battery life are not very different.
In fact, shallow discharge shallow charge is more beneficial for lithium battery, only when the power module of the product is calibrated for lithium battery, there is a need for deep discharge deep charge. Therefore, the use of lithium-powered products does not have to be bound to the process, all the convenience first, charge at any time, do not have to worry about the impact on life.
So ordinary charging state lithium battery also has the problem of life, each charge will also cause a little damage to the battery, only this damage is minimal, it takes up to a year or more to show up on the phone. So whether it is fast charging or ordinary charging will actually produce irreversible damage to the battery, but the damage of fast charging will be slightly stronger than the ordinary charging state. But from the current fast-charging technology under a variety of safeguards, this battery damage is still in a safe and reasonable state.
At present, the vast majority of companies providing fast-charging solutions are not from the battery point of view to give its impact on battery life, but the national standard for battery charging and discharging 500 times after the battery capacity of more than 80% are qualified, within a year on the use of the impact is not significant.