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How do you charge a lead acid battery for ups?

   lead acid battery for ups, also known as lead-acid accumulators, are rechargeable secondary batteries that use metallic lead as the electrodes and manganese dioxide or nickel sulfate as the positive active substance, and whose interior is filled with an electrolyte, usually dilute sulfuric acid. This type of battery converts chemical energy into electrical energy through a chemical reaction when discharged, and stores electrical energy back into the battery for subsequent use through a reverse chemical reaction when recharged. lead acid battery for ups is an important energy storage device, which realizes the storage and release of electrical energy through chemical reaction, providing convenience for our life and work. Although it has some shortcomings, with the progress of science and technology, it is believed that these problems will be gradually solved, and the performance and application areas of lead-acid batteries will be further improved.

    Lead-acid batteries are indeed rechargeable. As a traditional type of battery, lead-acid batteries are favored for their proven technology and wide range of applications. Below I will explain in detail why lead-acid batteries can be recharged and their charging process. It is worth noting that although lead-acid batteries can be recharged, there are a few things you need to pay attention to during their use. First, make sure you use the right charger and follow the correct charging procedure to avoid overcharging or overdischarging the battery. Second, lead-acid batteries generate a certain amount of heat during the charging process, so you need to make sure that the battery dissipates heat well to prevent damage due to overheating. In addition, lead-acid batteries should be regularly charged and maintained when they have not been used for a long period of time to maintain their good performance.

The charging steps for lead acid battery for ups are as follows:

    1. Wipe clean the battery case and electrode posts to ensure that there is no dust or dirt.

     2. Unscrew the refill hole cover and open the vent hole.

    3. The electrolyte with a specific gravity of 1.28 is slowly added to the battery, and the height of the liquid level should be kept 10~15 mm above the pole plate.

    4. After injecting the electrolyte, let the battery stand for 6 hours so that the electrolyte can fully saturate the pole plate.

    5. The charging process is divided into two stages:

      The first stage: the charging current for the battery capacity of 7 ~ 8%, charging until the battery voltage rises to 2.4 volts. The time from the start of charging to the generation of bubbles is about 26~30 hours.

     Stage 2: The charging current is half of the first stage and the charging time is 22~30 hours. At the end of charging, the voltage of a single cell should be 2.5~2.75 volts. During the 2~3 hours of charging, the power will reach a boiling state, at which time the voltage and the specific gravity of the electrolyte should remain unchanged.

    6. After the charging is completed, the charging and discharging process should be carried out for 2~3 times. When discharging, use a resistor in series with the battery, discharging the battery by 10% of the electric capacity. When the discharge voltage drops to 1.7 volts, charge again according to the above charging method. This is repeated until the battery capacity reaches 80% or more.

    7. After charging, adjust the specific gravity of the electrolyte in each single cell to make it equal. If the liquid level decreases, the electrolyte should be replenished to the specified height.


    It is important to note that charging should ensure that the environment is dry and tidy, and avoid the charger being wrapped in plastic bags or bottles, so as not to affect the heat dissipation. Try to use the original charger, and avoid overcharging for a long time, so as not to deform the battery and lose water. In addition, deep discharging the battery every 1 to 2 months will help activate the precipitated active substances and maintain the battery capacity. The above is only a general charging procedure, and the specific operation may vary depending on the battery model, specification and charger. Therefore, during actual operation, please be sure to follow the instructions in the battery manual or charger manual to ensure safe and effective charging of lead-acid batteries.


   Normally lead-acid batteries are able to be recharged based on their reversible chemistry. When the battery is discharging, lead oxide (PbO2) at the positive electrode and lead (Pb) at the negative electrode react chemically with sulfuric acid (H2SO4) in the electrolyte to produce lead sulfate (PbSO4) and water, while releasing electrical energy. While charging, this chemical reaction is reversed, i.e., the lead sulfate is reconverted to lead oxide and lead, while the electrical energy is stored back in the battery. This reversible chemical reaction allows lead-acid batteries to be charged and discharged repeatedly. Secondly, the charging process of lead-acid batteries requires an external power source. When we connect a lead-acid battery to a charger, the charger provides the proper voltage and current to induce the chemical reaction inside the battery to reverse. During the charging process, the charger monitors the state of charge of the battery and adjusts the charging parameters as needed to ensure that the battery can be fully charged safely and efficiently.

   The working principle of lead acid battery for ups is mainly based on the chemical reaction between its internal anode (PbO2) and cathode (Pb) and the electrolyte (dilute sulfuric acid). During the discharge process, the lead peroxide (PbO2) of the anode reacts with the sulfuric acid (H2SO4) in the electrolyte and the spongy lead (Pb) of the cathode to produce lead sulfate (PbSO4) and water (H2O), while releasing electrical energy. And during charging, this reaction is reversed, with the lead sulfate being reconverted to lead peroxide and spongy lead, and the electrical energy being stored back in the battery.

   lead acid battery for ups have many advantages, such as good reversibility of charging and discharging, the ability to discharge at high currents, simple structure, stability and reliability, and low price. This makes it widely used in many fields, such as automobiles, diesel locomotives start-up power supply, handling vehicles, pit and mining vehicles, submarines, electric bicycles, electric vehicles power supply, as well as substations, communication stations, standby power supply and so on. In recent years, with the continuous progress of technology, the performance of lead-acid batteries is also improving, such as the realization of maintenance-free sealed structure, and the rapid development of new types of batteries, such as colloidal batteries, lead crystal batteries, lead cloth batteries. However,lead acid battery for upsalso have some drawbacks, such as larger size and heavier weight, the risk of lead contamination and sulfuric acid leakage and corrosion, poor shock resistance, higher self-discharge rate, etc. Therefore, when using and maintaining lead acid battery for ups, it is necessary to pay attention to safe operation and avoid the occurrence of short-circuit, over-charging and over-discharging of batteries in order to prolong the service life of batteries.