As the name suggests, the biggest feature of maintenance-free lead-acid batteries is "maintenance-free". Compared with lead-acid batteries, its electrolyte consumption is very small, and there is basically no need to supplement distilled water during the service life. It also has the characteristics of shock resistance, high temperature resistance, small size, and small self-discharge. Of course, its price will be more expensive than lead-acid batteries. As for the service life, the recommended replacement period for maintenance-free batteries under normal conditions is about 3 years, which is equivalent to lead-acid batteries.
In order to avoid daily maintenance and maintenance, the design of the exhaust system is significantly different from that of lead-acid batteries, so theoretically, it is not necessary to add distilled water or electrolyte frequently. In addition, the housing of maintenance-free lead-acid batteries is generally closed, and unless there are professional tools and techniques, it is generally impossible to self-examine and repair.
Although the maintenance-free lead-acid battery is called "maintenance-free", it is not entirely possible to leave it alone. It is generally recommended to check the battery every 30,000 kilometers and maintain it every 80,000 kilometers. However, there are very few 4S shops or repair shops that can perform this operation, and the service life of the maintenance-free battery is relatively fixed. Under normal use, it should be replaced in 2-3 years, and there is nothing to extend its use. The way of life.
The sealed and maintenance-free lead-acid battery adopts the latest fully sealed structure and modern production technology designed in the 1990s. Make it have high performance, long life, pollution-free, maintenance-free, safe and reliable outstanding performance. Compared with traditional batteries, the capacitors of maintenance-free lead-acid batteries can work at an ambient temperature of -30℃~+60℃, and also have fast charging, high current discharge, low internal resistance, and a cycle life of more than 100,000 times. Advantages such as long life.
General battery lead-acid batteries are composed of positive and negative plates, separators, shells, electrolyte, and terminal posts. The chemical reaction of its discharge depends on the active materials of the positive plate (lead dioxide and lead) and the active materials of the negative plate. (Sponge pure lead) is carried out under the action of electrolyte (dilute sulfuric acid solution). The grid of the electrode plate is made of lead-antimony alloy in traditional batteries, and the maintenance-free battery is made of lead-calcium alloy. The former is made of antimony, and the latter is made of lead-calcium alloy. With calcium, this is the fundamental difference between the two. Different materials will produce different phenomena: traditional batteries will lose liquid during use. This is because the antimony on the grid will contaminate the spongy pure lead on the negative plate, which will reduce the reaction in the battery after being fully charged. 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, which reduces the electrolyte. Substituting calcium for antimony can change the back electromotive force of the fully charged battery, reduce the overcharge current, and reduce the liquid vaporization speed, thereby reducing the loss of electrolyte.
Maintenance-free lead-acid battery
Because the maintenance-free lead-acid battery uses a lead-calcium alloy grid, the amount of water that is generated during charging is small, and the amount of water evaporation is low. In addition, the shell is sealed, and the release of sulfuric acid gas is also very small, so it is comparable to traditional batteries. Compared with, it has the advantages of no need to add any liquid, less corrosion to the terminal posts and wires, strong resistance to overcharge, large starting current, and long power storage time. Maintenance-free lead-acid battery because its electrolyte only produces a small amount of gas under normal charging voltage, the plate has strong resistance to overcharging, and has small internal resistance, good low-temperature starting performance, and longer service life than conventional batteries. Features, so there is no need to add distilled water during the entire period of use, 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 lead-acid 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 repaired. Replace it.
Maintenance-free lead-acid batteries can also be recharged, and the charging method is basically the same as that of ordinary batteries. When charging, the voltage of each cell should be limited to 2.3-2.4V. Note that charging with conventional charging methods will consume more water, and the charging current should be slightly smaller (below 5A) during charging. Fast charging is not allowed, otherwise, the battery may explode and cause injury. When the hydrometer of a maintenance-free battery is displayed in amber or red, it means that the battery is close to being scrapped, and its service life will not be long even if it is recharged. Charging at this time can only be used as an emergency measure.
When conditions permit, maintenance-free lead-acid batteries can be charged with charging equipment with current-voltage characteristics. The device can ensure sufficient power and avoid excessive water consumption due to overcharging.
Precautions
The maintenance-free battery also needs to be recharged. If you have the following conditions, your battery must be recharged regularly:
A: I often drive short distances and the battery is not fully charged. Short-distance driving refers to driving within 20 kilometers per day and driving time within 20 minutes;
B: There are high-power electrical equipment installed on the car, such as car radios, amplifiers, and modified audio, and they are often used, especially when the car is off, the K battery is used for power supply;
C: often use headlights, fog lights, rear windshield heating, and air conditioning for a long time;
D: After parking, I often forget to turn off the on-board electrical equipment, such as various lights, radios, taxi overhead lights, taximeters, empty lights, etc.
E: The maintenance-free battery has a special structure, so its maintenance items such as water replenishment and recharging should be done by a professional department.