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Causes and prevention of battery swelling and explosion

Source:The unknownThe unknownTime:2020-02-05

Cause of battery swelling

1、Vent blockage

       If the vent hole on the charging cover of the battery is blocked or not unblocked, the gas generated in the case of too long charging time or too high charging voltage will gradually accumulate, thus leading to more and more pressure in the battery shell, finally leading to the battery bulging.

2、Charging time is too long

        As mentioned above, when the battery charging current is too large or the charging time is too long will produce a lot of gas. In addition, too much current or too long charging time will also lead to a rapid increase in the temperature of the electrolyte, which is also easy to lead to battery bulging.

3、The battery plate is vulcanized

        If the battery plate vulcanization, then in the process of charging, the single grid voltage and electrolyte temperature will rise rapidly, bubble generation earlier, and the reaction is violent, this time is easy to lead to battery bulging.

4、Start the motor continuously for too long

        When starting to start the motor, the battery should be within a short period of time the motor provides great electric current, and the large starting current will cause the battery violent chemical reaction, and will accompany gas generation, when the motor continuous use time is too long, will increase gas production, which increases the possibility of a battery up to crack.

5、The electrode lug and pole column in the battery are not solidly welded to the bus bar

        When the battery internal plate of the pole lug and pole column and busbar welding is not solid, if a large current discharge, welding will be too thin or poor contact and cause ignition, ablation phenomenon, this will produce sparks, the battery produced hydrogen and oxygen mixture gas ignited, resulting in battery explosion.

6、Electrolyte viscosity is too high

        If the electrolyte viscosity is large, it will easily lead to a slow penetration rate into the pores of the plate, which will also increase the internal resistance, so that the voltage drop consumed in the internal resistance in the discharge will increase. This will cause a rapid rise in the temperature of the electrolyte, and produce a large amount of gas, so that the internal gas pressure of the battery increased, causing the battery to bulge.

7、Too little electrolyte

        I believe we all know that the battery in use for a period of time will lead to the electrolyte reduction, at this point the need to add electrolyte or distilled water. When the electrolyte is reduced and the battery is overcharged, the battery bulges and even causes an explosion.

8、Charger damage

        When the charger or generator on the engine is damaged, the current or voltage may fluctuate, which may easily lead to a violent reaction in the battery, resulting in a large amount of gas, which then causes the battery to bulge.

 

How to prevent battery bulking

        The above said what causes the battery to bulge phenomenon. So we in the daily work and how to prevent battery bulging? So let's talk a little bit about that.

1、Control voltage and current. Above said, too much voltage or current easy to lead to battery bulging, so to control the voltage, current.

2、Try to control the charging time, do not let the charging time is too long, to prevent overcharging.

3、Choose a better charger or often check the generator on the engine, once found problems, timely maintenance or replacement, to avoid the cause of battery swelling.

4、In the process of charging, to ensure that the connection point is firm, because the connection point loose will produce sparks, which caused a hidden trouble for the battery bulging.

5、The vent hole is guaranteed to be open in time. In the ordinary maintenance, timely clean up the impurities around the battery.

6、Check the battery shell in advance whether there are cracks, electrolyte leakage. Because electrolyte once leakage, it is likely to penetrate into the cable or circuit, resulting in electrical connection, the generation of sparks.

7、Remove battery internal short circuit and plate curing in time. A short circuit in the battery produces a spark that ignites a mixture of hydrogen and oxygen gases, while vulcanization of the electrode plate produces a large amount of gas inside the battery. So, normally we should check the battery in time whether the internal short circuit, whether there is vulcanization phenomenon.

8、It is forbidden to use metal objects such as cables on the positive and negative pole column of the battery for lighting, which can easily cause the explosion of hydrogen and oxygen gas in the air, and even endanger personal safety.

9、Maintenance of electrical equipment should be the first to eliminate the battery internal flammable gas, because in the maintenance of electrical equipment, it is inevitable to produce sparks or lead to a large battery current generation, and this is a major safety hazard.

10、Check the quantity and density of electrolyte in time. This will protect the battery to a large extent, to prevent the battery bulging.

11、When starting the engine, try to avoid continuous starting for a long time.

There are three causes of the explosion:

1.、The high pressure in the battery causes the battery shell to explode

        By the working principle of the lead-acid battery know battery charging process, especially the late charge due to excessive charging, water into hydrogen and oxygen, short circuit, serious sulfide and charging the electrolyte temperature rise sharply, will make the water evaporated, at this time if the charging hole cover vent plug, because gas is too much too late to overflow, the pressure inside the battery will be rise very high, caused the accumulator tank deformation, when the internal pressure reaches a certain pressure will burst from the battery slot cover junction or other weak, it is a physical process. When the internal pressure of the battery is higher than 0.25mpa, the battery will burst at the joint of hot air or the corner of stress concentration of the tank cover.

2、The hydrogen explodes in a battery formed by an open fire

        The explosive limit of the mixture of H2 and O2 is 4%-96% of the volume of the mixture, and the explosive limit of the mixture of H2 and air is 4%-74% of the volume of the mixture. If 80% of the overcharge amount is used for electrolysis of water, the H2 content in the battery is greater than the explosion range. When the hydrogen content in the battery or the air accumulates to the explosion limit, an open fire will cause an explosion, which is a kind of chemical reaction.

        It is found that the explosion of the battery is a branch chain explosion reaction. This kind of explosion occurs too much in the case of overcharging, if the battery internal pole column, wall penetration welding and other places exist virtual welding spot, the probability of the battery explosion is higher. A qualified battery in normal use conditions will not occur spontaneous thermal explosion reaction. When the battery charging voltage of gasoline car is higher than 14.4v and diesel car is higher than 28.8v, the explosion may occur under the condition that the ignition exists simultaneously. Through the vehicle inspection of the battery explosion, it was found that most of the voltage regulator was defective and the battery was seriously overcharged.

3.、As a result of the battery vent plug, the battery first burst, the burst causes the battery vibration, the pole connection does not produce sparks, thus forming an explosion.

 

Methods to prevent battery explosion:

1、Control the amount of charge, but charge to reduce the amount of gas precipitation. Open fire is strictly prohibited in the charging room to keep ventilation.

2、During charging, the connection point should be reliable, and no spark will be generated due to looseness.

3、 In use, low voltage constant voltage charging, less gas output.

4、Prevent battery shell crack, electrolyte penetration.

5、When disassembling and disassembling the battery, the combustible mixture gas should be discharged automatically after the parking and then disassembling. When disassembling, first remove the negative pole line, then remove the positive pole line. When loading the battery, it is in the opposite order.

6、Keep the battery cover dry and clean.

7、Often check the battery small side vent, keep the vent open.

8、Control the battery level, to ensure that the liquid level in the specified range, electrolyte can not overflow.

9、Battery terminal connection wire should have lower contact resistance and greater contact pressure, and the connection is coated with vaseline to make it isolated from the external environment, to prevent the spark generated into the battery, ignition of combustible gas.

 

        In the ordinary use of the battery, as long as often check the battery, timely find the problem, timely eliminate the problem, the battery bulging phenomenon is not so easy to appear. So, we in the daily maintenance, must regularly check the battery.

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