Analysis of Tractor Battery Capacity

There are many reasons why tractors do not work properly, but sometimes people only pay attention to external problems. In some cases, it is the tractor's own problems. For example, the battery capacity has dropped.

The capacity of the battery is directly related to whether the tractor can start and operate normally. If the maintenance is not good, even if the new battery is installed, the capacity will drop rapidly and the service life will be shortened. What is the cause of the decrease in capacity? Here we come to know together:

One reason: plate vulcanization

That is, the white coarse grained lead sulfate gradually formed on the surface of the plate, which is hard and difficult to be dissolved in the electrolyte, and it is not easy to perform a reduction reaction with the electrolyte, thereby reducing the active material. In addition, the coarse-grained lead sulfate blocks the pores of the plate, making it difficult to infiltrate the electrolyte and increase the internal resistance, so that the active material participating in the reaction in the plate is reduced, resulting in a decrease in the capacity of the battery.

The causes of plate vulcanization are:

(1) The battery is in a state of complete discharge or semi-discharge for a long period of time. Due to changes in temperature, if the temperature is high, a part of the lead sulfate dissolves in the electrolyte. When the temperature is lowered, the lead sulfate dissolved in the electrolyte will be re-precipitated. Crystallize to form coarse crystals attached to the plates.

(2) The liquid level of the battery is lowered so that the upper edge of the battery is exposed to contact with air and oxidation, and then the oxidation part will contact with the electrolyte in the mechanical driving bump to produce coarse-grained lead sulfate, which will cure the upper part of the board.

(3) The specific gravity of the electrolyte is too large, the discharge current is too high and the temperature is too high, and the chemical reaction is intensified. The generated lead sulfate is quickly deposited on the plate, and it also promotes vulcanization. In order to prevent the vulcanization of the plates, the battery should always be kept in a fully charged state, the electrolyte should be submerged in the upper plate edge, and the specific gravity of the electrolyte should be properly selected according to the different regions and seasons.

Reason two: battery self-discharge

The fully charged battery is left unused and gradually loses its power, which is called self-discharge. Self-discharge is inevitable. Under normal circumstances, the discharge rate per day should not exceed 0.35%-0.5%.

The main reason for self-discharge:

(1) Impurities are contained in the plates or electrolytes, and potential differences between the impurities and the plates or between different impurities are generated, and they become a local cell. The circuit is formed by the electrolyte, and local currents are generated to discharge the batteries.

(2) The separator cracked, resulting in a short circuit between the positive and negative plates.

(3) Electrolyte or water is present on the surface of the battery case and becomes a conductor between the poles, causing the battery to discharge.

(4) Exfoliated active material and deposited on the bottom of the battery, causing short-circuit discharge of the plate. In order to reduce self-discharge, besides battery manufacturing materials should be as pure as possible, in the use of the shell surface and pile head must be kept clean, the electrolyte must be filled with chemically pure sulfuric acid and distilled water.

Reason 3: The active material on the plate falls off

During the normal use and charging and discharging of the battery, the volume of the active material of the electrode plate constantly expands and contracts, which causes the active material to slowly fall off. If the battery is used improperly, the active material will rapidly fall off and cause a short circuit. The main reason for the active material shedding on the polar plate is excessive current or temperature during charging, and frequent overcharging. When the discharge, the current is too large (such as access to the starter motor too long), so that the plate is curved (because the plate active material to participate in the degree of chemical reactions are inconsistent, resulting in inconsistent volume changes around the plate), can also cause the active material to fall off .

Reason four: shell crack or sealant cracked

Cracks will leak electrolyte and reduce the liquid level. If there are subtle cracks in the internal walls, the two cells communicate and the voltage drops. The main causes of cracks are battery holder screws that are too tight; knocking too fierce; vents blocked, gas can not be released, so that the single grid pressure is too large; winter freezing crack;