Although lead-acid batteries have been gradually replaced by lithium batteries, especially lithium iron phosphate batteries, which can perfectly replace them due to issues such as life, weight, and environmental protection, lead-acid batteries must be used in many cases. The theoretical design life of lead-acid batteries is about 5 years. Many manufacturers claim that they can be used for more than 3 years in real applications, but in fact, lead-acid batteries can only be used for about one to two years. Why does this happen, and what is it that shortens the life of lead-acid batteries?

　　Many people ignore these 5 reasons.

　　1. Imbalance

　　Most lead-acid batteries are not used alone, but are used together. Once the performance of one or two batteries is lagging, it will cause other batteries with good performance to not be used normally. This situation is called It is the imbalance of the battery.

　　2. Water loss

　　During the charging process of lead-acid batteries, electrolysis of water will occur to produce oxygen and hydrogen, and the water will be lost in the form of hydrogen and oxygen. Water plays a very important role in the electrochemical system. The reduction of water will reduce the ion activity involved in the reaction, reduce the contact area between sulfuric acid and the lead plate, which will increase the internal resistance of the battery and ultimately lead to a decrease in battery capacity.

　　3. Irreversible sulfation

　　After a lead-acid battery is over-discharged and stored in an empty state for a long time, its negative electrode will form a coarse lead sulfate crystal that is difficult to accept charging. This phenomenon is called irreversible sulfation. Slight irreversible sulfation can still be recovered by some methods; in severe cases, the electrode will fail and cannot be charged.

　　4. The plate is softened

　　The electrode plate is a material with multiple voids. During the repeated charge and discharge cycles of the battery, the efficiency of the electrode plate will gradually decrease as the different materials on the electrode plate alternately. In terms of appearance, it is the surface of the positive electrode plate. From the firmness at the beginning, it gradually becomes soft until it becomes mushy, at which time the battery capacity will drop drastically. High-current charging and discharging and over-discharging will accelerate the softening of the plate.

　　5. Short circuit

　　In the circuit, if the current does not flow through the electrical appliances, but is directly connected to the two poles of the battery, the battery is short-circuited. Because the resistance of the wire is very small, the current on the circuit will be very large when the battery is short-circuited. Such a large current will not be able to withstand the battery and will cause damage to the battery; more serious is that because the current is too large, the temperature of the wire will rise, and in severe cases, it may cause the circuit to catch fire.

　　Lithium-ion battery (LIB) has become the main energy storage solution in modern social life. Among them, lithium iron phosphate batteries are a perfect substitute for lead-acid batteries, and are the first choice for grid-connected peak shaving, off-grid energy storage, photovoltaic energy storage, UPS, data center and other industries.