Reasons for lead-acid batteries not charging properly
Why can't lead-acid batteries charge? If a palm battery cannot be charged after several months of use, the reason for this is partly due to the sulfation of the negative plate of the battery. This is because general constant voltage chargers may not be fully charged due to planned settings (such as using chargers that do not meet the requirements, such as low charging voltage or low current). Even if they can be charged or discharged during use, the capacity gradually decreases due to insufficient charging, and the lifespan will be shortened. On the other hand, the lack of voltage limiting control during discharge operation leads to overloading of the battery, resulting in frequent overdischarging and shortened battery life; On the other hand, due to poor usage habits, palm batteries are often not charged immediately after use, but are charged before the next use. This poor usage method will lead to a shortened battery life.
There are three main reasons for the sulfation of the negative plate of Parma batteries:
① Overdischarging: Discharging at a constant current or constant power to below the lower limit voltage of the battery is called overdischarging. For example, if 12V35AH is discharged from 3.5A to 10.8V, it should be stopped. If the discharge continues, it is considered overdischarging; Another quality issue with the equipment or controller is that although it is disconnected, there is current leakage and it is still discharging at a low current, which is also considered overdischarging.
② Undercharging: Running a battery for a long time without sufficient charge is called undercharging. For example, after the battery is discharged, it is charged, but if it is not enough, it is discharged again.
③ Failure to recharge in a timely manner: The battery was discharged but not charged in a timely manner. For example, if a battery is discharged and left unattended, it is considered as not being recharged in a timely manner.
The above three situations can all form sulfation of the negative electrode plate of the battery, which is manifested in the formation of a fine white lead sulfate crystal on the negative electrode plate. The conductivity of the lead sulfate crystal is poor, it does not participate in battery chemical reactions, and it is generated on the surface of the negative electrode plate, which also affects the reaction and utilization rate of other active materials. It will cause an increase in internal resistance and a decrease in capacity of the battery. According to Ohm's law, when the voltage remains constant and the resistance increases, the current decreases. This can lead to battery sulfation, and generally constant voltage chargers may not charge properly. Even if they can charge or discharge, their capacity will decrease and their lifespan will be shortened.
The degree of sulfation in batteries depends on the degree of over discharge, under charging, or failure to replenish electricity in a timely manner, as shown below:
1. The unevenness of the over discharge voltage, the magnitude of the current, and the number of times, the lower the over discharge voltage, the smaller the over discharge current, and the more times the over discharge occurs, the higher the degree of sulfation.
2. The unevenness of the undercharged voltage, the magnitude of the current, and the number of times, the lower the undercharged voltage, the smaller the undercharged current, the more times the undercharged, and the higher the degree of sulfation.
3. The length of time and number of times the electricity is not replenished in a timely manner. The longer the storage time, the more times it is stored, and the higher the degree of sulfation.