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Several Factors Affecting Sealed Battery Life

2021-01-18

  Sealed battery maintenance is indispensable. Whether it is a manual operation or maintenance or automatic monitoring and management, it is to detect the abnormal failure of individual batteries or the equipment system failure that affects the battery charging and discharging performance in time and actively take corrective measures to ensure the stability of the power system Operate reliably. The inspection and maintenance of batteries are divided into daily maintenance, quarterly maintenance, and annual maintenance.

  Several factors affecting battery life

  1. Deep discharge

  The depth of discharge has a great influence on the cycle life of the battery. If the battery is discharged frequently, the cycle of 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 and cannot be recharged in time, the sulfate particles produced are large, and the active material on the plate cannot be Full use, the actual capacity of the battery will gradually decrease in the long run, 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. Discharge rate

  Generally, 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 will be smaller than the rated capacity of the battery, and the discharge rate also affects the end of the battery. 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 are more prominent during high-current discharge, so the larger the discharge current, the smaller the capacity is 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 number of lead sulfate molecules produced, 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 outside 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 with a value of -3mV/°C. In the same way, an increase in ambient temperature can easily cause an over-discharge of the battery. The high temperature will also cause battery loss of water and thermal runaway. Temperature is a major factor that affects the normal operation of the battery. In solar photovoltaic systems, the controller is generally required to have a temperature compensation function.

  4. Partial Discharge

  5. High-temperature storage