Basic principle and maintenance of electric vehicle lead-acid batteries

ଲେଖକ: ଆଇଫ୍ଲୋପାୱାର - Portable Power Station Supplier

I. Battery working principle and characteristic electric bicycle battery is a reversible device for electrical energy and chemistry, which means that electric energy is stored (charging), and chemical energy is changed to electrical energy release (discharge). The electric bicycle battery is composed of a positive electrode plate, a negative electrode plate, a glass fiber separator, an electrolyte, and an electrolytic cell.

The active material of the positive electrode is a lead, the negative electrode active material is a sponge lead, the active substance of the two-pole plate after discharge All transformed into lead-sulfate, and after charging, it is restored to the original substance. The chemical reaction equation is as follows: Discharge PBO2 + 2H2SO4 + PBPBSO4 + 2H2O + PBSO4 Charging positive electrolyte negative electrode electrolyte negative electrode can be seen in the equation of chemical reactions, the sulfuric acid is consumed during discharge, and water is generated, so the electrolyte The concentration is getting smaller and smaller, and the charging process is opposite. Electric bicycles use an excessive design of negative electrode active substances.

When the battery is charged, the positive pole is 100%, the negative pole has not been charged to 90%, so that only the oxygen appearing in the battery, there is no difficulty composite hydrogen in the negative electrode. In order to solve the problem of water consumption, and must be a composite creation condition for oxygen. The ultra-fine fiber diaphragm plate film is designed to solve the transmission problem of oxygen, and the oxygen composite reaction is carried out, and the rethink of oxygen is completed, and the battery is sealed and maintained.

The rethink of oxygen is as follows: (positive) PBSO4 --------- Pbo --------- O2 (negative) PBSO4 --------- Pb --- --- (O2) Composite reaction 2, the failure mode of the battery and the positive electrode plate softening of the battery of the battery, the positive electrode plate of the battery is composed of the grid gate and the active material, wherein the active component of the active material is leaded lead. When the discharge is discharged, the lead is converted to a lead of sulfate, and the lead is converted into the lead in the lead when charging. 2, lead oxideαLead and<000000>beta;The leads of the lead, in whichαLead of lead oxide and support;<000000>beta;Lead oxide is an important lifting appliance.

In order to reduceαLead of levion is involved in discharge, and generally control discharge depth is 40%. The deeper the battery discharge,αThe more cornected leads, the more serious the positive plate softening, leading to the decline in the battery capacity, and form a vicious circle. The battery is often a large current discharge.

Therefore, the controller of the electric vehicle should implement a limited flow protection, which is based on this reason. B, the battery's negative plate vulcanization 1. After the battery is discharged, the lead converted to sulfuric acid Lead, if it is not timely charging or low charging voltage, some sulfuric acid lead crystals will gradually collect coarse sulfate crystals, which use ordinary charging methods that cannot be recovered, referred to as irreveneble sulfate, abbreviation.

2, when the ambient temperature in the winter is relatively low, the battery's floating voltage should be improved, otherwise the battery will appear, the battery is vulcanized. 3, the lost water is equivalent to the concentration of the sulfuric acid concentration of the electrolyte, and there is also a condition for accelerating battery vulcanization. 4.

Once the battery has vulcanization, it is impossible to solve it by simple floating and both, and other measures must be taken. Currently eliminating the chemical method of sealing battery vulcanization and uses small current pulse to vulcanize. Although the chemical method will eliminate the negative electrode plate vulcanization, it is newly discharged from the use of battery self-discharge.

This will form a new failure mode. C, the battery is lost and the thermal out of control 1. After the battery charges reaches 2.

35V (25 ¡ã C), it will enter a large amount of oxygen in the positive electrode plate, although the negative electrode plate has oxygen composite ability. However, if the charging current is too large, the oxygen composite reaction of the negative plate can not keep the epithelium, and the gas will open the exhaust valve to form a loss of water. If the charging voltage reaches 2.

42V (25 ¡ã C), the negative electrode plate of the battery will be hydrogen, and the hydrogen cannot be absorbed by the positive electrode plate, only the air pressure of the battery chamber can be added, and finally the ventilation chamber is lost. It is necessary to make a regular water supply to the battery, but the quality of the water and the requirements of the operator technology are very strict. 2.

The thermal displacement battery of the battery reaches a substrate 2.4V, this voltage exceeds a large amount of battery positive panel Voltage, especially in high temperature environments, a large amount of oxygen voltage drop, which occurs newly increased significantly. The oxygen that appears in the positive plate will be absorbed in the negative electrode plate, and the absorption oxygen is a significant exothermic reaction, and the temperature of the battery will rise.

Moreover, the oxygen composite reaction also has a current, and the new current leads to the charger that cannot be turned to the green lamp, which has been maintained in the high pressure stage. If the battery has excessive water, the fiber-fiber separator has a large new, which will accelerate the negative electrode plate to absorb oxygen, and there will be more heat, and the battery temperature is higher. The temperature rise of the battery will also accelerate the positive electrode plate to form a vicious circular heat loss.

In the thermal out-of-control state, the oxygen is added, and the air pressure in the battery has increased. When the glass spot temperature reaches the plastic battery case, the battery starts the transflation variant, in addition to the mechanical structure inside the battery, it will also Form a battery leakage, resulting in a more severe loss of water absorption. Although the phenomenon of battery thermal out-of control is not much, once thermal out of control occurs, the battery life will end rapidly in advance.

D, the imbalance of the battery 1, the battery necessarily exists in the manufacturing process. For example, the difference in the battery opening pressure can cause the battery to lose water. There is also an assembly pressure and polar weight imbalance or the like.

The battery is more than the amount of sulfuric acid of the battery rises, causing the battery open circuit to increase, and the charging voltage of the unit cell is equivalent to the other battery voltage, but The voltage allocated in the series battery group will decrease, forming an undermation of other batteries. Include in the under charge, the battery voltage will be lower when discharge, the charging voltage does not keep up, resulting in a higher battery voltage, low lower. The difference in the softening of the battery positive panel will be expanded as charge and discharge.

3. When the battery positive electrode plate is softened, the distal active material will block a portion of the micropores. The current density of the unit area on the positive plate will increase, resulting in the expansion shrinkage of the charge and discharge electroactive substance, and the positive plate softening is accelerated.

This is the resulting capacity backward battery more backward. 4. The larger the size of the sulfuric acid lead crystals, and its adsorption capacity is relatively added, resulting in a more serious vulcanization.

Therefore, the decline in battery capacity will also form a vicious circle. 5. About the imbalance of the battery pack, the only way to use the charging and discharge of a single battery periodically .

E, pulse repair eliminates the high voltage of the high-resistance of the thiol sulfate to high resistivity, or it can be broken Crystallization, if this high voltage is short enough, and the current limitation is performed, under the condition of the insulating layer, the charging current is not large, and it is not to form a large amount of gas. In this way, achieving lossless elimination vulcanization. F, the capacity of the battery and the detection of the common electric vehicle battery capacity representation is 12V10AH (2HR) its meaning: the battery is rated to 12V, the capacity is 10ah, 2HR represents 2 hours of discharge ratio (at a constant current to 10.

5V) When the discharge time is 2 hours) The standard capacity detection device is a 12V constant current discharge device, and there are 5A constant current, 10A constant current, and adjustable constant curren.