Introduction to Maintenance-Free Batteries

The sealed maintenance-free battery adopts the latest fully sealed structure designed in the 1990s and modern production technology. It has excellent performance of high performance, long life, pollution-free, maintenance-free, safe and reliable.
The general battery lead-acid battery is composed of positive and negative plates, separators, shells, electrolytes and terminal heads, etc. The chemical reaction of its discharge depends on the active materials of the positive plates (lead dioxide and lead) and the active materials of the negative plates (sponge-like pure lead) is carried out under the action of electrolyte (dilute sulfuric acid solution), in which the grid of the plate, the traditional battery is made of lead-antimony alloy, the maintenance-free battery is made of lead-calcium alloy, the former is made of antimony, the latter With calcium, this is the fundamental difference between the two. Different materials will produce different phenomena: traditional batteries will reduce liquid during use, because the antimony on the grid will contaminate the sponge-like pure lead on the negative plate, weakening the reaction in the battery after full charging. The electromotive force causes the excessive decomposition of water, and a large amount of oxygen and hydrogen escape from the positive and negative plates respectively, reducing the electrolyte. Replacing antimony with calcium can change the back electromotive force of the fully charged battery, reduce the overcharge current, and reduce the liquid vaporization rate, thereby reducing the loss of electrolyte.

Since the maintenance-free battery uses a lead-calcium alloy grid, the amount of water decomposition generated during charging is low, and the amount of water evaporation is low. In addition, the shell adopts a sealed structure, and the released sulfuric acid gas is also very small, so it is compared with traditional batteries. It has the advantages of no need to add any liquid, less corrosion to wiring pile heads and wires, strong resistance to overcharging, large starting current, and long power storage time.

The maintenance-free battery has the characteristics of low internal resistance, good low temperature starting performance, and longer service life than conventional batteries because the electrolyte only produces a small amount of gas under normal charging voltage, and the electrode plate has strong anti-overcharging ability. Therefore, there is no need to add distilled water during the entire use period, and under normal conditions of the charging system, there is no need to remove it for supplementary charging. However, the specific gravity of the electrolyte should be checked during maintenance.

Most maintenance-free batteries have a hole-shaped liquid (temperature-compensated) hydrometer on the cover, which changes color according to changes in the specific gravity of the electrolyte. It can indicate the storage state of the battery and the height of the electrolyte level. When the indicator eye of the hydrometer is green, it indicates that the battery is fully charged and the battery is normal; when the indicator eye has few green dots or is black, it indicates that the battery needs to be charged; when the indicator eye is light yellow, it indicates that the battery is faulty and needs to be repaired or to replace.

When conditions permit, the maintenance-free battery can be charged with a charging device with current-voltage characteristics. The device can ensure sufficient charge, and can avoid overcharging and consume more water.

Generally, this kind of maintenance-free battery can be stored for 10 months from the factory to the use, and its voltage and capacitance remain unchanged. The voltage and capacitance of the poor quality battery will drop about 3 months after leaving the factory. At the time of purchase, choose a product that is 3 months away from the production date, and you can check on the spot whether the voltage and capacitance of the battery meet the requirements in the manual. The quality is definitely not good either. It may be that the water-filled battery is disguised after being charged by the dealer.

Maintenance-free batteries can also be recharged, and the charging method is basically the same as that of ordinary batteries. When charging, the voltage per cell should be limited to 2.3-2.4V. Note that charging using the conventional charging method will consume more water, and the charging current should be slightly smaller (below 5A) when charging. Fast charging is not possible, otherwise, the battery may explode, resulting in injury. When the hydrometer of the maintenance-free battery is light yellow or red, it means that the battery is close to being scrapped, and the service life is not long even if it is recharged. Charging at this time can only be used as an emergency measure.