The reason for Lead acid battery cause of bulge
1. The air vent is blocked
If the vents of the lead-acid battery cover are blocked or not unblocked, the gas generated in the case of too long charging time or too high charging voltage will gradually accumulate, which leads to the increasing pressure in the battery shell and finally leads to the swelling of the battery.
2. Too long charging time
As mentioned above, when the lead-acid battery charging current is too large or charging time is too long, a large amount of gas will be produced.
In addition, too much current or too long charging time will also lead to rapid increase of electrolyte temperature, which is also easy to lead to battery bulge.
3. The battery plate is vulcanized
If the plate of the battery is vulcanized, then during the charging process, the single-cell voltage and electrolyte temperature will rise rapidly, the bubble will be produced early and the reaction will be intense, which will easily lead to the battery bulge.
4. The welding between the pole plate and pole and busbar in lead-acid battery is not firm
When the electrode ears and pole column of the battery plate in the battery are not welded firmly, if the large current discharge, the welding place will cause fire and ablation due to too fine contact point or poor contact, which will lead to spark and ignite the hydrogen and oxygen mixed gas generated by the battery, leading to battery explosion.
5. Excessive viscosity of electrolyte
If the viscosity of the electrolyte is large, it will easily lead to slow infiltration into the pores of the plate and increase the internal resistance, thus increasing the voltage drop consumed in the discharge.
This will cause the temperature of the electrolyte to rise rapidly and produce a large amount of gas, which will increase the gas pressure inside the battery and cause the battery to swell.
6. Too little electrolyte
As we all know, batteries after a period of use will lead to a reduction of electrolyte, when you need to add electrolyte or distilled water.
When the electrolyte is reduced, the overcharge will cause the battery to swell, and even cause explosion.
7. The charger is damaged
When the charger or the generator on the engine is damaged, the current or voltage may be large or small, which is easy to cause the battery to react violently, thus producing a large amount of gas, thus causing the battery to swell.
How to prevent lead acid battery bulge
1. Control the voltage and current.
As mentioned above, too much voltage or current will cause the battery to swell, so control the voltage and current well.
2. Try to control the charging time to avoid too long charging time and prevent overcharging.
3. Select a better charger, and repair or replace it in time once problems are found, so as to avoid causing battery bulge.
4. During the charging process, make sure all the connection points are firm, because spark will be generated if the connection point is loose, which will cause hidden trouble for the battery bulge.
5. Ensure timely and smooth ventilation.
In the ordinary maintenance, clean the battery in time around the impurities.
6. Check in advance whether there is crack in the battery case and whether the electrolyte leakage.
Because once the electrolyte leakage, it may infiltrate the cable or circuit, resulting in electrical connection, sparks.
7. Timely eliminate the internal short circuit of the battery and the plate vulcanization.
A short circuit in the battery produces a spark that sets off a mixture of hydrogen and oxygen, while a vulcanization of the plate produces a lot of gas inside the battery.
Therefore, the battery should be checked in time to check whether short circuit, whether there is vulcanization.
8. It is forbidden to fire metal objects such as cables on the positive and negative pole of the battery. In this way, it is easy to cause the hydrogen and oxygen gas with heavy air to explode.
9. When repairing electrical equipment, the flammable gas inside the battery should be excluded first, because when repairing electrical equipment, sparks will inevitably be generated or large electric current of the battery will be generated, which is also a major safety hazard.
10. Check the amount and density of electrolyte in time.
This will protect the battery to a great extent, prevent the battery bulge.
There are three causes of explosion
1. Excessive internal pressure of lead-acid battery causes explosion of lead-acid battery case
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, and the bursting position is located at the hot air junction of the tank cover or the corner of the stress concentration.
2. The hydrogen gas explodes in the battery formed by the open fire
The explosion limit of H2 and O2 mixture gas is 4%-96% of the volume of mixed gas, and the explosion limit of H2 and air mixture gas is 4%-74% of the volume of mixed gas.
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 air accumulates to the explosion limit, it will explode when exposed to open fire, which is a chemical reaction.
It is found that the explosion of battery belongs to the branch chain reaction.
Too many of these explosions occur in the case of overcharging. If there are virtual solder spots in the battery pole and through the wall welding, the battery has a higher probability of explosion.
A qualified battery does not undergo spontaneous thermal explosion under normal operating conditions.
3. Due to the blockage of the battery's exhaust port, the battery explodes first, which causes the battery to vibrate, and the poor connection of the pole leads to spark, thus forming an explosion.
Methods for preventing lead acid battery explosion
1. Control the charging amount, but charge to reduce the gas emission.
Open fire is strictly prohibited in the charging room and ventilation is maintained.
2. During charging, the connection point should be firm, and no spark will be generated due to looseness.
3. Low voltage constant pressure charging is adopted in use, with less gas output.
4. Prevent battery shell cracking and electrolyte penetration.
5. Keep the battery cover dry and clean.
6. Check the vents of the battery plug regularly to keep the vents open.
7. Control the liquid level of the battery to ensure that the liquid level is within the specified range and the electrolyte shall not overflow.
8. The connection wire of the battery terminal shall have low contact resistance and large contact pressure, and vaseline shall be applied at the connection to isolate it from the external environment, so as to prevent the spark from entering the battery and ignite the combustible gas.
In the ordinary use of batteries, as long as the battery often check, timely find problems, and remove problems, the phenomenon of battery bulge is not so easy to occur.
Therefore, in the daily maintenance, must remember to check the battery!
Source: UPS application network