Vulcanization characteristics of lead acid animal batteries:
Positive (Yang) pole: two lead oxide (lead powder) negative (negative) pole: the lead plate electrolyte (dilute sulfuric acid) adsorbed in the cavernous body (isolation plate)
The problem of the positive plate is the drop of the lead powder (softening), and the negative plate appears as a crystal blocking channel formed by vulcanization.
The good quality charger is mainly embodied in three aspects: high charging efficiency, low failure rate, and prolonging battery life.
The four main factors that affect battery life are vulcanization, polarization, battery pack imbalance, overcharge and overcharge.
Vulcanization (sulfation): when discharge, a solid white lead sulfate is produced on the plate, and it is very difficult to convert into the active substance of lead sulfate when charged. This lead sulfate has poor conductivity, large resistance, low solubility and dissolution rate, difficult recovery and blocking the electrolyte and deep activity. The contact path of material becomes the reason for the reduction of capacity and the shortening of life. Its appearance is: once the light is released, the battery is full. We call it the "false damage" of the battery. Sulphide sulfate is adhered to the plate, reducing the reaction area of the electrolyte and the plate, thus rapidly reducing the capacity of the battery. The loss of water will aggravate the sulfuration of the battery. Sulfurization will aggravate the loss of water and lead to a vicious cycle.
Causes: long term storage, insufficient charging, over discharge, and high current discharge during operation.
Hazards: slight battery vulcanization will reduce battery capacity, increase internal resistance of battery, and lose electrode when it is serious.
Fault performance:
1. due to the reduction of the active substances in the plate, the capacity of the battery decreases, the capacity of the battery is obviously insufficient, and the voltage drops rapidly.
2. because the lead sulfate crystal can not be fully reduced, the electrolyte density is reduced.
3. as the capacity of the battery is reduced, the voltage of the battery rises quickly when the battery is charged, and the bubble is precipitated too early. The battery voltage is quickly reduced when the battery is discharged.
4. the resistance increases. When the battery is charged, the temperature of the electrolyte rises very fast, and it rises to 40 degrees rapidly.
5. starting charging and charging ends, the battery terminal voltage is too high.
6. there will be bubbles when charging bubbles or charging.
General charger manufacturers solution: periodic overcharging method, reducing the battery lead sulfate crystallization; in the floating charge stage adding a single pulse, in fact, basically no effect of vulcanization.
Our company's product solutions: combined pulse and temperature compensation
Combined pulse: the combined pulse is added in the constant current and constant pressure stage. Using the peak pulse in the intelligent pulse, it interferes the vulcanization of the battery during the charging process and breaks the crystal nucleus of the lead sulfate, making it difficult to form the sulfate and play a repair role.
Temperature compensation: through the accurate collection of external and internal temperature by the thermosensitive electronic, intelligent adjustment of the charging voltage, so that the battery will not be under charge and overshoot, the maximum reduction of vulcanization.
Polarization: ohmic polarization, electrochemical polarization, concentration polarization
1. ohm polarization: caused by the resistance of each part of the battery, its pressure drop follows Ohm's law, the current decreases, the polarization decreases immediately, and the current disappears immediately after the current is stopped.
2. electrochemical polarization: polarization caused by the retardation of electrochemical reaction on the electrode surface. As the current becomes smaller, it decreases significantly in microseconds.
3. concentration polarization: due to the retardation of ion diffusion in the solution, the polarization of the electrode surface and the solution body concentration is poor under a certain current. This polarization decreases or vanishes at the macroscopic second level (from a few seconds to tens of seconds) as the current drops.
The first two polarization only needs the battery's current to drop to small enough or stop to be reduced or eliminated in milliseconds or microseconds, mainly by the battery manufacturer, and the concentration polarization is solved by the charger.
General charger manufacturers solution: set the safety voltage range, overvoltage protection, prevent the polarization caused by high voltage. But the defect is to set the voltage of the control as a fixed value, which can not be accompanied by the change of the environment and the change of the voltage caused by the thermal reaction in the charging process, and the optimal charge voltage range is precisely controlled. To put it simply, only a theoretical control voltage is roughly set.
Our company's product solutions: temperature compensation, combined pulse.
Temperature compensation: to control the voltage accurately and control it below the poling point (for floating charge stage: monomer 2.42V-2.45V).
Combined pulse: a variety of pulses are combined into a pulse group to achieve the best effect of charging and depolarizing. The composite pulse charging current is accompanied by an instant depolarization while charging, which effectively reduces the resistance polarization, concentration polarization and electrochemical polarization of the battery charging. For example, the rectangle pulse is the main source of charge power, and the reverse single pulse mainly solves the concentration polarization and the change of the internal resistance of the battery; the gap pulse mainly solves the resistance polarization. Therefore, the charging current of a variety of pulse combinations can achieve the best depolarization effect, the charging efficiency is greatly improved, the heating of the battery charging is greatly reduced (that is, the temperature rise is very low), which not only makes the large current charging possible, but also saves the charging time and energy, and can also prolong the service life of the battery charger.
Battery pack imbalance: a battery consists of more than one single battery. Because of the manufacturing process, the absolute balance of each battery can not be achieved, and the average charger uses the average current.