Leakage of Battery and Solution Measures

Generally, when the battery is used for more than one year, a single battery will leak the terminal of the electrode column, and the positive electrode is more serious than the negative one. This is a common problem in domestic batteries. Through the anatomical structure of the pole terminal leakage battery, the pole terminal is corroded, and sulfuric acid flows along the corroded channel to the surface of the cell under the internal pressure, resulting in leakage.
Relatively speaking, the hot melt adhesive seals better. If the melting temperature and time are well controlled, and the seal is clean and free of fouling, the seal is reliable. After dissecting the leaked batteries with hot-melt seals, it was found that the leaked batteries had a hot-melt layer at the seals and a honeycomb-shaped bubble cap, which was not very dense. Oxygen will carry acid under certain pressure because of the presence of oxygen inside the battery. The fog leaked along the passage of the sand cave. The battery parts that leak acid easily are mainly:
1. The seal between the top cover and the bottom groove is not good or due to collision, the sealant ruptures and leaks.
2. Safety valve leakage and leakage.
3. Terminal acid leakage.
The causes of leakage in different parts are different, so comprehensive analysis should be carried out, and then corresponding measures should be taken to solve the problem. For hot-melt sealed batteries, the temperature and time of hot-melt should be strictly controlled, and the hot-melt surface should be kept clean and tidy. Firstly, the combination of hot melt adhesive and adhesives is sealed with hot melt adhesive and sealed with sealant.
(1) Safety valve leakage
Maintenance-free battery safety valve will be sealed under certain pressure. If the pressure exceeds the prescribed pressure (opening pressure), the safety valve will automatically open and deflate to ensure the safety of the battery. The main causes of safety valve leakage are as follows:
1) Adding too much acid, the battery is in an oil-rich state, the gas channel of oxygen conversion is blocked, the oxygen increases, the internal pressure increases, the opening pressure exceeds, the safety valve opens, and the oxygen belt opens. The acid mist was released. If the relief valve is opened many times, the acid mist will form an acid solution around the relief valve.
2) The anti-aging performance of safety valve is poor.
After the battery is used for a period of time, the rubber of the safety valve will be eroded by oxygen and sulfuric acid, the elasticity will be reduced, the opening pressure will be reduced, and even the long-term opening state will produce acid mist and liquid leakage.
Safety valve leakage treatment method:
1) The safety valve is made of anti-aging rubber (e.g. fluorine rubber) to prolong the aging time.
2) In order to ensure the safety of the safety valve, the safety valve should be replaced regularly.
3) Change the structure of safety valve to adjust its opening pressure. At present, the structure of the column safety valve is relatively perfect, which makes the rubber used have good aging resistance and adjustable pressure. When it is found that it is aging (open pressure drop), it can be adjusted appropriately to increase the open pressure to ensure its sealing.
(2) Pole terminal leakage
The sealing quality between the pole and the shell cover of YUASA battery is also one of the main factors affecting the cycle life of the battery. The sealing structure of the pole has resin sealing structure, resin double sealing structure, mechanical compression sealing structure and HAGEN patent pole sealing structure. The common method of pole seal is to weld the pole to the lead bushing on the battery cover, and then seal it with a layer of epoxy sealant. Usually, when the battery is used for more than one year, the terminal of a single battery pole leaks electricity, and the positive electrode is more serious than the negative one.  This is a common problem in domestic batteries. Through the anatomical structure of the cell leaking at the pole terminal, the pole terminal has been corroded, and sulfuric acid flows along the corroded channel to the surface of the cell at the internal pressure to cause leakage. This phenomenon is also known as acidity or leakage, and terminal corrosion is caused by oxygen corrosion in acidic conditions.
Lead oxide and lead sulfate produced by corrosion are porous. Under the action of internal pressure, sulfuric acid will climb outside the corrosion hole and cause leakage. Relatively speaking, the corrosion rate is relatively slow, so liquid leakage will occur after a long time of use. The corrosion rate of positive electrode is higher than that of negative electrode, so the leakage of positive electrode is more serious. As the welding is usually carried out by acetylene oxygen welding, a layer of lead oxide is formed on the oxide surface during the welding process, which is easy to react with sulfuric acid, thus accelerating the corrosion rate and shortening the leakage time.
Solving the leakage of pole terminal:
1) Inert gas shielded arc welding (such as hydrogen arc welding) is used to prevent the welding surface from being oxidized and slow down the corrosion rate.
2) Elevate the pole terminal to prolong the height of sealing layer and prolong the time of corrosion and leakage.
3) Eliminate the welding seal method and use rubber compression seal to block oxygen passage and delay corrosion rate. If the seal height of the pole terminal is reasonably designed, it may leak during the service life of YUASA battery.