General battery lead-acid battery is composed of positive and negative plates, partitions, shells, electrolyte and junction pile head, etc., the chemical reaction of its discharge is dependent on the positive plate active material (lead dioxide and lead) and negative plate active material (spongy pure lead) in the electrolyte (dilute sulfuric acid solution) under the action of the grid, where the plate, the traditional battery made of lead-antimony alloy, maintenance-free batteries are made of lead-calcium alloy The former uses antimony, the latter uses calcium, which is the fundamental point of difference between the two. Different materials will produce different phenomena: traditional batteries in the use of the process will occur in the liquid phenomenon, this is because the antimony on the grid frame will contaminate the sponge-like pure lead on the negative plate, weakening the fully charged battery after the counter-electromotive force, resulting in excessive decomposition of water, a large number of oxygen and hydrogen respectively, from the positive and negative electrode plates escape, so that the electrolyte is reduced. Use calcium instead of antimony, you can change the fully charged battery after the counter electromotive force, reduce the overcharge current, the liquid vaporization rate is reduced, thus reducing the loss of electrolyte.

As the maintenance-free battery adopts lead-calcium alloy grid frame, the amount of water decomposition produced during charging is less, the amount of water evaporation is low, coupled with the shell using a sealed structure, the sulfuric acid gas released is also very little, so it has the advantages of no need to add any liquids, less corrosion on the junction pile head and wires, strong resistance to over-charging, high starting current, and long time of storage of power, etc., compared to the traditional storage battery.

Maintenance-free battery because of its normal charging voltage, the electrolyte only produces a small amount of gas, the plate has a strong resistance to overcharging ability, and has a small internal resistance, low-temperature starting performance, than the conventional battery service life, etc., and therefore do not need to add distilled water throughout the use of the period of time in the charging system in the normal case, do not need to be removed from the supplementary charging. However, the specific gravity of its electrolyte should be checked during maintenance.

Most of the maintenance-free battery in the cover with a hole-shaped liquid (temperature-compensated) specific gravity meter, it will be based on the specific gravity of the electrolyte changes and changes in color. It can indicate the battery's storage status and the height of the electrolyte level. When the specific gravity meter indicator eye is green, indicating that the charging has been enough, the battery is normal; when the indicator eye green dot is very little or black, indicating that the battery needs to be charged; when the indicator eye shows a yellowish color, indicating that the battery has internal faults, need to be repaired or replaced. Conditions, maintenance-free batteries can be used with current-voltage characteristics of the charging equipment for charging. This equipment can ensure adequate power, but also to avoid overcharging and consume more water. Generally this kind of maintenance-free battery from the factory to use can be stored for 10 months, its voltage and capacitance remain unchanged, poor quality in the factory about 3 months after the voltage and capacitance will fall.

    In the purchase of the election from the date of production of 3 months, on the spot can check the battery voltage and capacitance to meet the requirements of the manual, if the voltage and capacitance have decreased the situation shows that it is inside the material is not good, then the quality of the battery is certainly not good, there may be a watered-down batteries after the dealer charging camouflaged into. Maintenance-free batteries can also be supplemental charging, charging and ordinary battery charging method is basically the same. Charge each single cell voltage should be limited to 2.3-2.4V. Note that the use of conventional charging method charging will consume more water, charging current should be slightly smaller (below 5A). Rapid charging should not be carried out, otherwise, the battery may explode, resulting in injury. When the specific gravity meter of the maintenance-free battery, showing a yellowish or red color, indicating that the battery is close to the end of life, even if rechargeable, the service life is not long. Charging at this time can only be used as an emergency expedient.

Common lead-acid battery repair problems and treatment methods

1, maintenance-free battery (hereinafter referred to as battery) in charging basically does not produce gas bubbles, can be in a sealed state, eliminating the need to add acid and other maintenance work. However, the battery in the charging and discharging process to be completely free of gas is impossible, in order to release the gas, the battery can not be completely airtight. Pry open the upper plastic cover of the battery, you can see each small battery has a rubber cap on top of the liquid filling hole, the battery water can be evaporated out through the rubber cap. Even if the battery is not in use, the water will evaporate, resulting in a decline in battery capacity, and in severe cases, the battery will be dry and can not be charged and discharged. For this kind of battery, as long as the battery to add distilled water or pure water, and then a few charge and discharge cycle, most of the capacity of the battery can be restored. Example: a 12V7.2Ah battery, the use of time is not long, charging to 14V after discharge, short-circuit current is only more than 300 mA. Uncovered check, the liquid has nearly dried up, injected distilled water and charge-discharge cycle twice, the capacity is restored to 84%, has been able to work normally.

2, the battery in the discharge, the electrolyte sulfuric acid concentration and and specific gravity decline, fully discharged, at 15 ℃ when the specific gravity fell to 1.11. General charging specific gravity rise, the specific gravity of the summer full of electricity for 1.25 ~ 1.26, winter 1.27 ~ 1.28. Because the battery is in the sealing state, in the use of the battery can only be used according to the battery's voltage to determine whether it has been charged or discharged. 6V and 12V battery is fully charged, the capacity has returned to 84%, has been able to work normally. 12V battery is fully charged, the voltage is 6.8V~7V and 13.6V~14V respectively, when fully discharged, the voltage of 6V and 12V battery is 5.3V and 10.6V respectively. if the battery is over-discharged or in the semi-discharged state for a long period of time, the battery will be sulfurized, and sulfurized batteries can't be eliminated by adding distilled water and regular charging, only when charging with a relatively low concentration of sulfuric acid in electrolyte, the sulfurization can be eliminated. Only when the concentration of electrolyte sulfuric acid is low, the sulfation can be eliminated.

If the sulfation of the battery is not serious, the capacity does not drop much, can be used to charge the battery for a long time with a small current (0.05A or less). If the sulfation of the battery is more serious, it can be charged to the highest voltage (6V battery charged to 7V, 12V battery charged to 14V), the electrolyte in the battery with a syringe to draw out, and then injected into the distilled water, in order to dilute the electrolyte. Charge 1~2 hours and then pump out the electrolyte, inject distilled water, repeat the above operation until the specific gravity of the electrolyte pumped out is no longer a significant rise until (generally 2~3 times can be). At this time, try to anti-electrolyte extraction, and then according to the ambient temperature into the specific gravity of 1.25 ~ 1.28 sulfuric acid, discharge and then full of electricity, check the specific gravity of the electrolyte. If the specific gravity is small, pump out the electrolyte again and inject sulfuric acid, so that the specific gravity of the electrolyte reaches the standard. Note that the electrolyte injected into the battery should not be more, to be spongy substances in the battery to absorb the electrolyte can be full, the excess electrolyte pumped out, the repair work is completed. Example: a SonyBP603Ah battery, is used in the 1980s for 3/4-inch camera power supply, the battery sulfurization is serious. Repair using the above method, the capacity is restored to 2.2Ah.

3, some batteries connecting bridge or battery to the external lead wires broken (most cases are positive and negative lead wires broken), the battery can not work. Variant of the battery, only to find the broken parts can be repaired. Using the above method of copper-plated money, use a multimeter to find the voltage is not normal or the output current is small battery, the fracture point is in the battery. After finding, in the break on the plastic cover to open a hole, the size of the hole to be able to use a soldering iron to reach into the break for welding to the extent that it should not be too large. After welding, after checking the connection is normal, with plastic or epoxy resin to open the hole closed, and then resurrected with the above method, the battery can be put back into work.

4, if the battery internal short-circuit failure, available low voltage current to burn off the short-circuit point. If there is active material off (manifested as brown material in the extracted electrolyte), indicating that the battery life is over, this type of battery does not have to repair. However, if only one or two of the battery life end, the one or two batteries can be short-circuited, the remaining battery can still be used as a lower voltage battery.