The amount of electricity discharged or the length of discharge time under specified conditions (including discharge intensity, discharge current and discharge termination voltage) is called battery capacity.
From life practice, we can find that whether it is a starting battery or an energy storage type, as long as it is used for a long time, no matter how long it is charged, the power seems to be used up quickly. This is what we call capacity reduction.
The positive plate is the main factor affecting the working life of this battery. The capacity of charge and discharge cycles, especially the capacity decrease under deep cycling, is closely related to the quality deviation of the positive plate. The corrosion rate of the grid depends on the composition of the grid alloy, but the higher the storage temperature, the faster the corrosion rate, the deeper the discharge depth, and the more serious the corrosion. With such aging, the battery will no longer be able to charge.
In normal operation, the PbSO4 particles on the negative plate are small and can easily return to fluffy lead after discharge. However, sometimes lead sulfate that is difficult to reduce is generated inside the battery, which is called sulfation. There are many reasons for negative electrode salinization, such as failure to charge in time after discharge, long-term storage of the battery, causing severe self-discharge, excessive electrolyte concentration, long-term insufficient charging, and long-term discharge at high temperatures. This kind of lead sulfate is difficult to restore by conventional methods. Such a reduction in active material will inevitably affect the capacity of Jinma lead-acid batteries.
Capacity generally refers to the capacity that can be released by discharging at a rate of 10 hours at 25°C. For a single discharge, an increase in temperature will increase the discharge capacity, and a decrease in temperature will decrease the discharge capacity. However, for long-term use, rising temperature will shorten the battery life, while low temperature can extend the battery life. This is mainly due to the working principle.
Frequent power outages, long power outages, and irregular power outages in base stations result in frequent charging and discharging. According to the dissection of scrapped Jinma batteries in base stations by current manufacturers, the cause of end of life is the sulfation of the negative plate, which is early capacity failure. (PCL) is a typical phenomenon.