What are the reasons for the explosion of UPS power lead-acid batteries?

Reasons for the explosion of UPS power supply lead-acid battery The UPS power supply lead-acid battery is charged to the end, after the two poles are converted into effective substances, and then continue to be charged, a large amount of hydrogen and oxygen gas will appear. H2: O2 is precipitated in a volume of 2:1. According to the electrochemical equivalent of hydrogen and oxygen gas, 0.4181L of hydrogen and 0.20907L of oxygen will appear for every 1Ah overcharged. When the concentration of this mixed gas occupies 4 in the air, it will explode when it encounters an open flame, which will damage the battery in the slightest, and injure people and objects in the severe case. 1. Excessive internal pressure of the battery causes the battery shell to explode. Due to the working principle of the UPS power supply battery, during the battery charging process, especially at the end of the charging stage, due to overcharging, water is decomposed into hydrogen and oxygen, short circuit, severe sulfidation, and rapid electrolyte temperature during charging. Rising will cause a large amount of moisture to evaporate. At this time, if the vent hole of the filling hole cover is blocked, because there is too much gas to overflow, the pressure inside the battery will rise very high, causing the Leoch battery tank to deform first. When the internal pressure reaches a certain pressure It will burst from the junction of the battery tank cover or other weak points, which is a physical process. When the internal pressure of the battery is higher than 0.25MPa, the battery will burst, and the burst location is located at the hot air junction of the tank cover or the corner where the stress is concentrated. 2. The explosion limit of the H2 and O2 mixed gas formed by hydrogen encountering open flame is 4%-96% of the volume of the mixed gas, and the explosion limit of the mixed gas of H2 and air is 4%-74 of the volume of the mixed gas. %. If 80% of the overcharge is used for water electrolysis, the H2 content inside the battery is greater than the explosion range. When the hydrogen content in the battery or in the air accumulates to the explosion limit, it will explode when exposed to an open flame. Kind of chemical reaction. The study found that the explosion of the battery is a branched chain explosion reaction. Too many explosions of this kind occur in the case of overcharging. If there are virtual solder joints in the battery internal poles, through-wall welding, etc., the explosion probability of the battery is higher. A qualified battery will not react with self-heating and explosion under normal conditions of use. When the battery charging voltage is higher than 14.4V for gasoline vehicles and 28.8V for diesel vehicles, an explosion may occur under the condition that the fire exists at the same time. Through the inspection of the vehicle with the battery exploded, it was found that most of the voltage regulators were defective, and the battery was in a serious overcharge state. 3. Due to the blockage of the battery vent, the Leoch battery burst first. The burst caused the battery to vibrate, and sparks appeared when the pole wiring was not secure, thus causing an explosion. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: What is the difference between alkaline batteries and carbon batteries?