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Treatment method and phenomenon analysis of leakage of VRLA battery
- Sep 09, 2018 -

Analysis of treatment methods and phenomena:

Analysis of battery leakage phenomenon

Relationship between leakage of battery and electrolyte quantity

A basic principle of sealed battery design is to use lean liquid technology, so that the O2 produced by the positive electrode can be absorbed on the negative electrode by recycling in the battery to the greatest extent, so as to complete the re-combination of gas inside the battery, maintain the balance of water in the electrolyte, so that the battery can be sealed. If the amount of electrolyte is too much, the internal gas recombination channel will be blocked, the gas inside the battery will increase, the pressure will increase, and the leakage will easily occur at the defective part of the battery seal. Therefore, the amount of acid added to the battery must be moderate. As far as discharge rate of sealed battery is concerned, the density of electrolyte is generally controlled at 1.10 and 1.30 before discharge. The minimum acid consumption per Ah battery can be calculated according to the cell reaction. The amount of pure H2SO4 needed before discharge is W (H2SO4) = V. D. m, the amount of pure H2O is W (H2O) = V. D (1 - m), and the amount of pure H2SO4 required after discharge is W (H2SO4) = V. D. n - 3. 36.

Note: for each release of 1 Ah, consumption of pure H2SO4 3.66 g and production water 0.67 G. The density of the electrolyte at the beginning of the discharge is 1.30; the percentage concentration of the starting weight of the discharge is 38%; the percentage concentration of the weight after the discharge is 16%; and the volume of sulfuric acid at the concentration of D.

In order to achieve depletion, it is necessary to ensure that the electrolyte required must be completely adsorbed in the baffle, and there are some gas channels, generally every Ah added to the glass fiber baffle 17 g, each g baffle saturated acid absorption of 0.8 ml. Therefore, the maximum amount of acid absorption is 13.6 ml, ensuring that the maximum amount of acid absorption can not exceed 95%, generally 92%, that is, the maximum amount of acid addition is 12.5 ml, the amount of acid addition should be controlled between 10.9-12.5 ml. 3.2 battery leakage location analysis

Through long-term use observation, it is found that the leaky parts of the battery mainly lie in the sealing place between the battery groove cover, the safety valve place and the sealing place of the pole terminal. There are different reasons for leakage in different parts. A comprehensive analysis should be carried out and corresponding measures should be taken to solve them.

Leakage treatment of lead-acid battery: sealing method of tank cover

The seal of battery cover is generally made of 2 methods: epoxy adhesive sealing and hot melt sealing. Relatively speaking, the hot melt sealing effect is better, by heating the battery cover plastic (ABS or PP) hot melt pressure fusion together. If the melting temperature and time are well controlled and the seal is clean and filthy, the sealing is reliable. Anatomical observation on the hot-melt sealed leaky cell showed that there was a hot-melt layer in the sealed place with honeycomb trachoma, which was not very dense. Owing to the existence of O2 in the cell, O2 leaked along the trachoma channel with acid mist under certain pressure. Epoxy adhesive bonding seal leakage is more, especially when lying battery. If the epoxy adhesive formula and curing conditions are well controlled, sealing can be achieved. After dissecting the leaky battery, it was found that the sealant was interfacial bonding with the shell, the bonding force was not strong, and it was easy to fall off, and there were holes or cracks in the leak. Due to poor fluidity of epoxy adhesive (especially low temperature curing), it is easy to cause some parts of the sealing groove not filled with glue, resulting in leakage channels. Cracks (small cracks) mainly occur in the horizontal discharge cell of the rack. Due to gravity, the deformation of the rack makes the battery sealant layer stress, and the curing of epoxy adhesive is very brittle. Under the action of external force, it is easy to crack. Cracking produces leakage.

Believe that through the above introduction of leak treatment of lead-acid batteries have some understanding of it, we pay more attention to these phenomena in daily life, hoping to help everyone.

Tianneng Battery Group Co., Ltd.