Problems and maintenance of electric vehicle batteries

The problem and maintenance of electric vehicle batteries is the reason for this problem. 1.1 It is caused by the battery itself. Why do you say that? We know the working principle of lead-acid batteries. The charging and discharging process of lead-acid batteries is an electrochemical reaction process, charging At the time, lead oxide, lead oxide and discharge are reduced to lead sulfate. And lead sulfate is a very short-lived crystalline substance. When the electrolytic solution of the battery contains high concentration of lead sulfate or a static place for too long, it will score and form a small crystal. These small lead sulfate crystals attract the surroundings. Like a snowball, it forms a large lazy crystal. After the crystallization, the charged lead sulfate can not return to lead oxide, it will accumulate more and more on the plate electrode, and the operating area of u200bu200bthe plate will be reduced. This phenomenon is called vulcanization. At this time, the battery capacity will gradually decrease until it becomes unusable. When many lead sulfate deposits also attract lead particles to form a lead branch, the positive and negative plates between the lead branches form a short circuit of the battery. Assuming that there are cracks on the surface of the board or the sealed plastic shell, lead sulfate crystals will accumulate in these cracks, and expansion tension will appear. After all, the breakage and drop of the board or the rupture of the shell constitute irreparable physical damage to the battery. Therefore, the important mechanism leading to the failure and damage of lead-acid batteries is that the battery itself cannot prevent vulcanization. 1.2 Reasons for battery processing In view of the particularity of lead-acid batteries for electric bicycles, various battery manufacturers have adopted a variety of methods. The typical method is as follows: the number of new plates. The original single 5-block and 6-block grid system was changed to 6 blocks and 7 blocks, 7 blocks with 8 blocks, or even 8 blocks with 9 blocks. By reducing the thickness of the plates and separators, and adding the number of plates to increase the capacity of the battery. The specific gravity of sulfuric acid in travel batteries. The ratio of sulfuric acid in the original floating rechargeable battery is generally between 1.21 and 1.28, while the ratio of sulfuric acid in the battery of the electric bicycle is generally between 1.36 and 1.38, which can supply large current and the initial capacity of mobile batteries. The dosage and ratio of the active material lead oxide added to the positive plate. When lead oxide is added, the electrochemical reaction material participating in the discharge is added, the discharge time is added, and the battery capacity is added. Through these methods, the initial capacity of the battery meets the capacity requirements of the electric bicycle, especially the high-current discharge characteristics of the battery are improved. However, with the addition of the plates, the capacity of sulfuric acid is reduced, the heat of the battery causes a large amount of water loss, and the probability of the battery's micro short circuit and lead bypass is increased. The acid ratio is increased again to the initial capacity of the battery, however, the vulcanization is more serious. One of the most basic principles of a sealed battery is that after oxygen is released from the positive plate, it directly enters the negative plate, is absorbed by the negative plate, and is reduced to water. In this way, the water loss of the battery is very small, and the free protection is free water after the end. Therefore, the load-bearing capacity of the negative plate is higher than the load-bearing capacity of the positive plate, which is also called negative transition. Adding active materials to the positive plate will inevitably lead to the reduction of negative transition, the deterioration of the oxygen cycle, the loss of water and the increase of vulcanization. Although these methods operate on batteries of initial capacity, they will constitute water loss and sulfide, which will promote each other, after all, the effect is to sacrifice battery life. The assembly of the polarity group also has a virtual welding problem. The short-term appearance of false soldering is a local plate. Each battery has 15 electrodes in a single cell, which means there are 15 welds. A battery has 6 single cells, which is 90 welds. A battery consists of three 12V batteries, which is 270 welding points. If there is a virtual weld on a solder joint, the capacity of a single battery will decrease, and then a single battery will form a reverse battery. The entire battery is reversed, and the battery will form a serious imbalance, which will make the battery pack Premature invalidation. Even if the virtual welding is controlled at one ten thousandth, there will be a unified virtual welding for every 37 batteries, which of course is not allowed. Disclaimer: Some pictures and content of articles published on this site are from the Internet, please contact to delete if there is any infringement. Previous: Analysis of the application characteristics of lithium batteries