What are the common factors that affect battery capacity?

There are many factors that affect the battery capacity, and the common ones are the following: (1) The influence of the discharge rate on the battery capacity The battery capacity decreases with the increase of the discharge rate, that is to say, the greater the discharge current, the greater the calculated battery capacity Small. For example, a 10Ah battery can be stored for 2 hours with 5A discharge, that is, 5×2u003d10; then 10A discharge can only discharge 47.4 minutes of electricity, which is 0.79 hours. Its capacity is only 10×0.79u003d7.9A So about a given battery discharged at different time rates, there will be different capacities. When we talk about capacity, we must know the time rate or rate of discharge. Simply put, how much current is used to discharge. (2) The influence of temperature on battery capacity. Temperature has a great influence on the capacity of lead-acid batteries. Generally, as the temperature decreases, the capacity decreases. The relationship between capacity and temperature is as follows: Ct1u003dCt2/1+k(t1-t2).t1t2 They are the temperature of the electrolyte, k is the temperature coefficient of the capacity, Ct1 is the capacity (Ah) when the temperature is t1, and Ct2 is the capacity (Ah) when the temperature is t2. In the battery processing standards, it is generally necessary to specify a temperature as the rated standard temperature If it is stipulated that t1 is the actual temperature and t2 is the standard temperature, (usually 25 degrees Celsius) the negative plate is more sensitive to the influence of low temperature than the positive plate. When the temperature of the electrolyte decreases, the viscosity of the electrolyte increases, and the ions receive greater resistance , The diffusion capacity decreases, and the electrolyte resistance increases, which increases the resistance of the electrochemical reaction, and a part of lead sulfate cannot be converted normally. The charge acceptance ability decreases, resulting in a decrease in battery capacity. (3) The influence of termination voltage on battery capacity After discharging to a certain voltage value, the voltage drops sharply. In fact, the energy obtained is very small. If the battery is discharged for a long time, the damage to the battery is considerable. Therefore, the discharge must be terminated at a certain voltage value, and the cut-off discharge voltage is called discharge Termination voltage. Setting the termination voltage of discharge is of great significance to prolong the service life of the battery. Generally, the discharge termination voltage of the electric vehicle battery we repair is 1.75 volts per cell, which means that a 12 volt battery is 6 cells , Its discharge termination voltage is 6×1.75u003d10.5 volts. [2](4) The influence of the geometric size of the electrode plate on the battery capacity is when the amount of active material is on time, the geometric area of u200bu200bthe electrode plate directly in contact with the electrolyte is increased. The increase in battery capacity, so the geometric size of the electrode plate, the influence of the battery capacity cannot be ignored. ①The influence of the electrode plate thickness on the capacity The amount of active material is certain, and the battery capacity decreases with the increase of the electrode plate thickness. Thicker, the smaller the contact surface between sulfuric acid and the active material, the lower the utilization rate of the active material, and the smaller the battery capacity. ②The influence of the height of the electrode plate on the capacity In the battery, the utilization rate of the active material in the upper and lower parts of the electrode plate exists. Larger differences, experiments have confirmed that at the beginning of discharge, the current density of the upper part of the electrode plate is about 2 to 2.5 times higher than that of the lower part. This difference gradually decreases with the passage of discharge, but the current density of the upper part is greater than that of the lower part. ③The influence of the area of u200bu200bthe electrode plate on the capacity The amount of active material is constant, the larger the geometric area of u200bu200bthe electrode plate, the higher the utilization rate of the active material, and the larger the capacity of the battery. In the case of the same battery shell and the same active material quality , The use of thin plates to increase the number of plates, that is, to increase the effective reaction area of u200bu200bthe plates, thereby increasing the utilization rate of active materials and increasing the capacity of the battery. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.