The impact of battery use on the battery

1. The working chemistry of batteries and water loss in batteries :

Pb+PbO 2 +2H2SO 4 ←→ 2PbSO 4+2H2O

2H2O←→ 2H 2↑ +O 2↑

Pure lead, lead dioxide and diluted sulfuric acid are used as electrolytes, which can charge the plates. As the battery discharges, the lead oxide positive active material and the lead sponge negative material act together in the dilute sulfuric acid electrolyte to form lead sulfate and water. This reaction process is reversed when charging. The generated water is electrolyzed into hydrogen and oxygen during the charging process, which are released to cause water loss in the battery. The more frequent the charging process, the higher the water loss rate. Excessive water loss will cause the battery to dry up and eventually fail.

2. The impact of temperature on battery life:

Temperature will affect the battery life, especially when the temperature is above 25 °C. Generally speaking, when the average ambient temperature is above 25 °C, the expected battery life will be reduced by half compared to the designed life for every 8 °C increase.

3. The capacity of the battery decreases in the later stage of use, eventually causing battery failure:

The positive and negative grids form the main structure of the lead-acid battery. The grids are used to hold the active material and direct the current out of the battery during discharge and into the battery during charge. Since the active material actually generates current in the grids, the interface between the grid and the active material is a very important area of ​​the battery, and the quality of this interface has a decisive influence on the performance of the battery. When an AGM battery starts to cycle, the inner plates should be formed in a few cycles and the capacity will increase. Then the cycling continues, and the capacity of all batteries begins to decrease year by year. In the later stages of battery life, the battery capacity decreases significantly. If a failed grid is carefully examined, it is found that the battery failure is caused by the formation of an insulating sulfide layer at the boundary between the grid and the active metal. This insulating sulfide layer electrically insulates the active material from the grid, thus causing the battery to have a high internal resistance and a concomitant decrease in capacity.

4. Internal short circuit of the battery in the later stage of use:

During the use of the battery, some lead sulfide is deposited on the negative plate. Lead sulfide has a tendency to be difficult to handle, that is, it hardens over time, resulting in permanent loss of capacity. This situation may occur for any type of battery. If this sulfidation continues for a period of time so that the sulfide forms a mass, it can grow over the entire separator and connect to another plate. This sulfidation phenomenon is called sulfidation bridging or short circuit. The charging process of the entire battery becomes dangerous.

Based on the above situation, batteries should be replaced in time in some important positions to avoid accidents. Generally, batteries with a floating charge design life of 10 years should be replaced after 5 years of use; batteries with a floating charge design life of 20 years should be replaced after 10 years of use to ensure the effective capacity of the battery pack and the safe and stable operation of the battery pack.