Several factors affecting battery life

The depth of discharge has a great influence on the cycle life of the battery. If the battery is often deeply discharged, the cycle life will be shortened. Because the deep discharge of the battery with the same rated capacity means that high-current charging and discharging are often used. During high-current discharge or often under voltage, it cannot be recharged in time. The sulfate particles produced are large, and the active material on the plate cannot be removed. Full use, the actual capacity of the battery will gradually decrease in the long term, which will affect the normal operation of the battery. Since solar photovoltaic power generation systems are generally not prone to overcharging, long-term power deficit is the main reason for battery failure and shortened life in solar photovoltaic systems. 2. The discharge rate generally stipulates that the capacity of the 20-hour discharge rate is the rated capacity of the battery. If you use a discharge rate lower than the specified hour, you can get a battery capacity higher than the rated value; if you use a discharge rate higher than the specified hour, the discharged capacity is smaller than the rated capacity of the battery, and the discharge rate also affects the battery terminal Voltage value. When the battery is discharged, the electrochemical reaction current is preferentially distributed on the surface closest to the main solution, resulting in the formation of lead sulfate on the electrode surface and blocking the inside of the porous electrode. The above-mentioned problems become more prominent during high-current discharge, so the larger the discharge current, the smaller the capacity given by the battery, and the faster the terminal voltage value declines, that is, the end-of-discharge voltage value decreases with the increase of the discharge current. But on the other hand, it’s not that the lower the discharge rate, the better. Studies have shown that a long-term discharge rate that is too small will significantly increase the amount of lead sulfate molecules generated, causing stress to cause the plate to bend and the active material to fall off, which will also reduce the use of the battery. life. 3. The external temperature is too high. The rated capacity of the battery refers to the value of the battery at 25°C. It is generally considered that the working temperature of the valve-regulated sealed lead-acid battery is within the range of 20~30°C. When the battery temperature is too low, the battery capacity is reduced, because the electrolyte cannot fully react with the active material of the electrode plate under low temperature conditions. The capacity reduction will not be able to meet the expected backup use time and remain within the specified depth of discharge, which will easily cause over-discharge of the battery. Judging from the external parameters of the battery, the voltage has a great relationship with the temperature. Every time the temperature increases by 1°C, the voltage drop of a single cell drops by 3mV. In other words, the voltage of a lead-acid battery has a negative temperature coefficient, and its value is -3mV/°C. For the same reason, the increase in ambient temperature will easily cause the battery to over discharge. High temperature will also bring about the phenomenon of battery loss of water and thermal runaway. Temperature is a major factor affecting the normal operation of the battery. In solar photovoltaic systems, the controller is generally required to have a temperature compensation function. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete it.