Lithium battery manufacturers explain in detail why it is best to charge and discharge lithium power batteries

Figure 1) It is often heard that lithium batteries need shallow charging and shallow discharging. What is shallow charging and shallow discharging? How should we achieve shallow charge and shallow discharge? The following lithium battery manufacturers explain in detail the statement about shallow charging and shallow discharge of lithium batteries, and how to achieve shallow charging and shallow discharge in actual use, so as to extend the service life of lithium batteries. What is shallow charge and shallow discharge? After decades of development in the battery industry, we have gone from the early nickel barrier, lead-acid and other types of batteries to lithium batteries with better performance. Compared with other batteries, lithium batteries are lightweight, without memory effect, and Higher energy density is favored by the market. Why is the voice of shallow charge and shallow discharge after upgrading the lithium battery getting louder and louder? This should start with the habit of all people using batteries for a long time. Before the large-scale application of lithium batteries, the mainstream power batteries on the market should be lead-acid batteries. The low price and strong current output of lead-acid batteries basically meet the driving operation of most equipment on the market. However, lead-acid batteries have a strong memory effect. If the power is not fully used, it will easily lead to shorter and shorter battery life. In the period of lead-acid batteries, people often respond when the battery life is significantly shortened. After deep discharge (continuous use, until completely out of power) for several times, the battery life will be restored to a part. (In actual situations, this kind of deep discharge cannot be used frequently, and frequent over-discharge will also cause the battery to fail. ) But this method is not suitable for lithium batteries, which have no memory effect. When the battery life is shortened, in addition to the normal capacity loss, and it may be that a certain battery cell of the lithium battery is abnormal, it will cause the entire battery to work abnormally. Therefore, when the battery life of the lithium battery is insufficient, it is necessary to pay close attention to what causes it. Rather than over-discharging to see if it can solve the problem, under normal circumstances, when the lithium battery has been abnormal, then over-discharging will increase the severity of the problem. For daily use with lithium batteries, we should fully charge the battery and use two-thirds of the battery to align and charge immediately. This is the best state. Almost all lithium battery charger settings on the market are compared. Full state, so we may not be able to realize the shallow charging of the lithium battery. Generally speaking, the shallow charging of the lithium battery refers to the best charge to about 90%. Generally, few people are willing to try this operation. Because giving up this part of the capacity is also a waste. With the upgrading of the technology level of lithium batteries currently on the market, we can ignore the shallow charging in performance, and we only need to pay attention to the habit of shallow charging in daily use. Why should I charge shallowly? As mentioned above, what is shallow charge and shallow discharge, why do we need shallow charge and shallow discharge when using lithium batteries? We need to start with the characteristics of the lithium battery itself. It is worth noting that lithium battery cells are very afraid of overcharging and overdischarging without the protection board access. Both overcharging and overdischarging will cause permanent damage to the lithium battery. In severe cases, the battery may be damaged, and in severe cases, a fire and explosion may occur. Therefore, lithium batteries are more afraid of overcharging and overdischarging. In addition, the lithium battery pack is composed of multiple single lithium batteries (see Figure 1). Even with the current best technology, it is still impossible to make all the values u200bu200bof a batch of batteries be at the same value. There are some slight differences in the parameters of each of them. Such as capacity, internal resistance. The capacity and internal resistance will cause a slight difference between the full and discharged energy of each battery. The battery pack will be equipped with a BMS battery re-discharge management system (referred to as a protection board) for use. When there are more batteries connected in series. Manufacturers will add the function of automatic equalization when designing. Automatic balancing can make some subtle corrections when large variables appear in each string of battery packs. But this usually needs to be achieved during the charging process. If the variable has exceeded the value that can be balanced. There is no way for automatic equalization to completely correct it, and this kind of error will become bigger and bigger in the long run. The imbalance of the battery pack follows. When lithium battery pack manufacturers produce lithium battery packs, they generally use the same batch of lithium batteries as raw materials. The purpose is to better maintain the consistency of lithium batteries (consistency means that all the battery cell parameters in the same battery pack are as close as possible to infinitely). Under normal circumstances, the normal charge and discharge curves of these batteries are very close, so it is also the best choice to make battery packs. But even so, when the battery cell undergoes abnormal charging and discharging, the various parameters of the battery cell may have slight changes, which is also a characteristic of the lithium battery pack. The purpose of shallow charging and discharging is to make the battery be used in a normal environment as much as possible. Avoid overcharging and over-discharging that may cause some abnormal fluctuations in the single cells, which will cause the final battery pack to fail to work. Therefore, shallow charging and discharging is a theoretically supported method of using lithium batteries. And from the perspective of the characteristics of lithium batteries, shallow charging and shallow discharge are also more in line with the normal use of lithium batteries. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.