In the inter-vehicle use process, the battery is not able to be depleted due to long-term shelving, after the vehicle is turned off, the appliance is not turned off, the electricity is not frequently turned on, or the power is continuously used, the generator is not working properly, the power is short, and the battery is depleted. Normal squatting. The battery in the depleted state should be replenished in time to make the battery fully charged and return to normal use. If the power is lost for a long time, the battery capacity will drop or the damage will be discarded in advance. In the 1960s, American scientist Mass made a pilot study on the charging process of the battery, and proposed an acceptable charging curve for the battery based on the premise of the most outgassing rate, as shown in Figure 1. Tests show that if the charging current changes according to this curve, the charging time can be shortened and the battery life is not affected. The principle calls this curve the best charging curve. It can be seen from Figure 1 that the initial charging current is very good, but the attenuation is very fast. The main reason is that the charging process produces polarization. In the process of charging maintenance-free battery charging, oxygen and hydrogen are generated inside. When oxygen cannot be absorbed in time, it accumulates on the positive plate (the positive plate generates oxygen), so that the internal pressure of the battery is increased, the temperature of the battery rises, and the positive plate is reduced. The area is manifested by an internal resistance rise and a so-called polarization phenomenon. It is clear that the charging process and the discharging process are mutually inverse reactions. The reversible process is the thermodynamic equilibrium process. In order to ensure that the battery can always maintain a balanced state of charge, the current through the battery must be made smaller. The ideal condition is that the applied voltage is equal to the electric potential of the battery. However, it has been shown that when the battery is charged, the applied voltage must be increased to a fixed value, and this value exceeds the balanced electric potential of the battery to varying degrees due to various factors such as electrode material and solution concentration. In the chemical reaction, the phenomenon that this electric enthalpy exceeds the thermodynamic equilibrium value is the polarization phenomenon. In general, there are three reasons for the polarization phenomenon. 1) An ohmic polarization charging process in which positive and negative ions migrate to the two poles. In the ion migration process, a certain resistance is inevitably received, called ohmic internal resistance. In order to overcome this internal resistance, the applied voltage must be applied with a predetermined voltage to overcome the resistance and push the ion migration. This voltage is converted to the environment in a thermal manner, with so-called ohmic polarization occurring. As the charging current increases sharply, ohmic polarization will cause the battery to heat up during the charging process. 2) When the concentration polarization current flows through the battery, in order to maintain a normal reaction, the most ideal situation is that the reactants on the surface of the electrode can be replenished in time, and the product can be removed in time. At the same time, the diffusion rate of the product and the reactant is much faster than the rate of the non-chemical reaction, thereby causing a change in the concentration of the electrolyte solution near the electrode plate. That is to say, the electrolyte concentration distribution is not uniform from the electrode surface to the portion of the solution. This phenomenon is called concentration polarization. 3) Electrochemical polarization This polarization is caused by the speed of the electrochemical reaction carried out by the electrode, which is delayed by the speed at which the electrode is transported electronically. For example, before the negative electrode of the battery is discharged, the surface of the electrode has a negative charge, and the solution in the vicinity has a positive charge, and the two are in equilibrium. When discharged, electrons are immediately released to the battery. The negative charge on the surface of the electrode is reduced, while the oxidation of the metal dissolves slowly Me-e? Me+, can not replenish the electron surface reduction on the electrode surface in time, and the charged state of the electrode surface changes. This state of surface negative charge reduction promotes the movement of metal electrons from the ruthenium electrode, and the metal ion Me+ is transferred into the solution to accelerate Me-e? The Me+ reaction proceeds. There is always a moment to reach a new balance of state. However, compared with before discharge, the number of negative charges on the surface of the electrode is reduced, and the potential of the electrode corresponding thereto becomes positive. That is, the electrochemical polarization voltage becomes high, which seriously hinders the normal charging current. Similarly, when the positive electrode of the battery is discharged, the number of positive charges on the surface of the electrode is reduced, and the potential of the electrode becomes negative. These three polarization phenomena are all severe with the increase of the charging current. The conventional charging system was designed based on the internationally recognized rules of thumb before 1940. Its most famous is the "Ampere Hours Rule": the charging current amperage should not exceed the number of hours the battery is to be charged. At the same time, the speed of conventional charging is limited by the temperature rise of the battery during charging and the generation of gas. This phenomenon is important for the shortest time necessary to charge the battery. In general, there are three types of conventional charging. 1. Constant current charging method The constant current charging method is a charging method in which the output voltage of the charging device is adjusted or the resistance in series with the battery is changed, and the charging current intensity is kept constant, as shown in FIG. 2 . The method of tanning is simple, but since the acceptable current capability of the battery is gradually decreased as the charging process progresses, the charging current is mostly used to electrolyze water and generate gas to make the gas out too late. Therefore, the stage charging method is often used. . 2, stage charging method This method includes a two-stage charging method and a three-stage charging method. 1) The two-stage method uses a combination of constant current and constant voltage, as shown in Figure 3. First, the constant current is charged to a predetermined voltage value, and then the constant charging is performed to complete the remaining charging. The conversion voltage between the two phases is the constant voltage of the second phase. 2) The three-stage charging method uses constant current charging at the beginning and end of charging, and is charged with constant voltage. When the current decays to a predetermined value, the second phase is switched to the third phase. This method can reduce the outgassing to the worst, but it is used as a fast charging method and is subject to certain restrictions. 3. Constant voltage charging method The voltage of the charging power source maintains a constant value during the entire charging time, and the current gradually decreases as the battery terminal voltage gradually increases. Compared with the constant current charging method, the charging process is close to the optimal charging curve. Fast charging with a constant voltage, as shown in Figure 4. Since the battery charge potential is relatively high in the initial stage of charging, the charging current is very large, and the current will gradually decrease as the charging progresses. Therefore, it is only necessary to simply control the system. This method of charging is very irritating and avoids overcharging of the battery. However, in the initial stage of charging, the current is excessive, which has a great influence on the battery life, and it is easy to bend the battery plate, thereby causing the battery to be scrapped. In view of this shortcoming, simple constant voltage charging is very difficult to use, and it is only used when charging the power supply voltage and current. For example, in a car running process, the battery is charged by a constant voltage charging method. When the charger is used for constant voltage charging of the battery, an improved constant voltage charging method should be adopted, that is, the current limit is limited, so that the current limit does not exceed 0.25 of the battery capacity to prevent damage to the battery. The reaction of the battery is reversible, and the chemical reaction of its discharge and charging is as follows: PbO2+Pb+2H2SO4→PbSO4+2H2O (discharge) PbSO4+2H2O→PbO2+Pb+2H2SO4 (Charging) When the battery is in normal use, the active substances (Pb02 and Pb) of the positive and negative plates are partially converted into small granular crystals of lead sulfate. These soft small granular crystals of lead sulfate are uniformly distributed in the porous active material during charging. It is easy to contact with the electrolyte to restore the original substances PbO2 and Pb. If the small-grained lead sulfate cannot be converted into a living substance in a timely and effective manner due to improper use and maintenance, the lead sulfate of the crystal grain will be gradually formed, and the vulcanization phenomenon of the plate is formed to form a white hard lead sulfate crystal on the plate. It is very difficult to convert lead sulfate into a living substance during charging. These coarse and hard lead sulfate crystals have poor conductivity and thus block the pores of the active material of the plate, hindering the penetration and diffusion of the electrolyte, and increasing The internal resistance of the battery, at the same time, when charging, this crude and hard lead sulfate is not as good as the soft small crystal lead sulfate is converted into PbO2, and Pb. If it takes too long, these coarse and hard lead sulphate will lose reversible effect, resulting in the reduction of the effective material of the plate, the discharge capacitance and the shortened service life. The loss of battery means that the lead sulfate of the electrode is not completely converted into a living substance. If the battery is in a deficient state for a long time, the battery will be vulcanized. There are several phenomena in the sulphation of lead-acid battery plates: (1) The lead-acid battery rises rapidly during the charging process, and its initial and final voltages are too high, and the final charging voltage can reach 2.90V/single grid. (2) During the discharge process, the voltage drop is very fast, that is, it drops to the termination voltage too early, so its capacitance is significantly lower than other batteries. (3) When charging, the temperature of the electrolyte rises rapidly and easily exceeds 45 °C. (4) At the time of charging, the density of the electrolyte is normal, and bubbles are generated prematurely during charging. (5) When the battery is dissected, the color and state of the plate are found to be abnormal. The positive plate is light brown (normally dark brown), the surface of the plate has white lead sulfate spots, and the negative plate is grayish white (normally gray). The surface of the plate is rough, it feels like sand when touched, and the plate is hard. (6) Severe sulfation, the white crystals of lead sulfate formed by the plates are coarse, and cannot be restored into living substances under normal conditions. Regular judgment of maintenance-free battery loss 1. When the battery terminal voltage is at 12.3V, there is a loss of electricity and the loss phenomenon is divided into: a) Minor power loss: The terminal voltage is 11.7V~12.3V. b) Loss of power: The terminal voltage is 10V~11.7V. (lightly vulcanized) c) Serious power loss: the terminal voltage is at 10V. (degree and severe vulcanization) 2. The color of the battery capacity display (electric eye) is white. According to the output mode of the charger and the degree of power loss of the battery, the appropriate charging method is selected by three charging methods: 1, constant voltage charging: With constant voltage 16V, 6-QW-68an battery current limit 17A 6-QW-90an battery current limit 22A, charging 4 to 12 hours. The charging time depends on the degree of battery loss. This charging method is suitable for batteries that are slightly depleted. 2. Staged constant current charging: Phase 1: The 6-QW-68 battery is charged with constant current 7A until the voltage rises to 14.4V and then enters the stage. The 6-QW-90 battery is charged with constant current 9A until the voltage rises to 14.4V and then enters the stage. Phase 2: The 6-QW-68 battery is charged for 6 to 20 hours with a constant current of 3.5A. The 6-QW-90 battery is charged for 6 to 20 hours with a constant current of 4.5A. The charging time depends on the battery's power loss. This charging method is suitable for batteries that are depleted. 3, constant current and small current charging The 6-QW-68 battery is charged for 20 to 40 hours with constant current 3A. The 6-QW-90 battery is charged for 20 to 40 hours with a constant current of 4A. The charging time depends on the battery's power loss. This charging method is suitable for batteries that are severely depleted. 4, charging process considerations During the charging process, the battery temperature should be less than 50 °C. When the battery temperature reaches 45 °C, the charging current should be halved and the charging time should be extended accordingly or the battery temperature should be stopped until the battery temperature drops. 5, the judgment of the end of charging 1) The battery voltage does not change at 16V and is stable for 3 hours. 2) The battery capacity display (electric eye) does not change in green. 3) If necessary, the electric eye is rotated, and the density of the electrolyte is measured to 1.28 g/cm3 by a density meter, and the stability does not change. If the three points are reached at the same time, it indicates that the battery has been charged, and the battery can be stopped and stopped to resume normal use. Induction Cooker Main Board,Motor Starter Button,Ignition Starter Switch For Foton,Main Spindle Induction Motor Ningbo Zhenhai Rongda Electrical Appliance Co., Ltd. , https://www.centrifugalswitch.com
