There's a clever way to control the consistency of lithium batteries

The consistency of lithium battery production is an industry-recognized blueprint. Although the differential coefficient method, the standard deviation wash method and the threshold method are used to screen relatively consistent batteries by voltage, internal resistance. However, after the battery is formed into a group, it is difficult to maintain the battery consistency within the battery group, which is affected by many factors, such as temperature field, battery polarization, self-discharge, etc.

Therefore, the control of battery consistency in the battery pack is particularly important. At present, the battery management system is generally used in the industry to control the consistency and safety of the battery in the battery pack, thereby protecting the battery pack and prolonging the service life of the product. The battery management system (BMS) can realize the control of the relative consistency of the battery, thereby avoiding the overcharge and over discharge which may be caused during the use of the battery due to the inconsistency of the battery, and prolonging the service life of the battery pack. The battery management system with equalization function has a certain degree of inconsistency in the battery pack to maximize the capacity and energy utilization of the battery pack.

It can be seen from the analysis of the experimental data that the battery pack with MBS is charged by a charging and discharging device or a charger, and the highest voltage appears at the initial stage of constant voltage charging. The initial small voltage inconsistency of the battery in the battery pack is objectively present, although the initial voltage inconsistency is small, and a certain balance can be obtained during the constant voltage charging process, and the battery voltage inconsistency is adjusted to some extent. However, in the long-term use, the battery in the battery pack is inevitably intensified under the catalysis of temperature field, etc., which may cause overcharge or over discharge in the battery during charging and discharging. Of course, the battery management system also is inevitable that the charge and discharge capacity of the score battery will be sacrificed under the premise of ensuring safety to ensure the consistency between the batteries.

When the battery pack with 50% unbalanced setting is charged by the charging and discharging device or the charger, when the charging enters the constant voltage or the like constant voltage stage, the battery in the battery pack reaches its own maximum voltage. At this time, the voltage between the batteries also some adjustments are made, but the charging device will overcharge the battery and the voltage will be adjusted. However, the charging device will cause overcharging of the battery and the adjustment of the voltage inconsistency is small, and the charger can not only prevent the single battery. Overcharge, the balance of inconsistency is relatively obvious.

In summary, the highest voltage of the battery in the battery pack is often in the initial stage of constant voltage charging. The inconsistency between the batteries in the battery pack is inherently objective, and more from the long-term use process, each time the charging and discharging cycle will not lead to generate large voltage difference between the battery and charge status differences, namely larger will not lead to inconsistent. The management system in the battery pack can also adjust the inconsistency in the process of charging and discharging to a certain extent, and can also prevent the battery from overcharging in the case of extreme imbalance.

The page contains the contents of the machine translation.