The charging and discharging process of lead-acid batteries for electric vehicles is an electrochemical reaction process. Lead sulfate forms lead oxide when charging, and lead oxide is reduced to lead sulfate when discharging. Lead sulfate is a substance that is very easy to crystallize. When the concentration of lead sulfate in the electrolyte in the battery is too high or the static idle time is too long, it will "agglomerate" and form small crystals.
These small crystals attract the surrounding lead sulfate again, forming large inert crystals like snowballs. Crystallized lead sulfate can't be reduced to lead oxide when charging, and it will also precipitate and adhere to the electrode plate, resulting in the reduction of the working area of the electrode plate. This phenomenon is called vulcanization, which is often called aging. At this time, the battery capacity will gradually decrease until it cannot be used.
Coiling method
1, check whether the product identification of electric vehicle battery is complete. Including the manufacturer's name, product specification and model, manufacturing date and trademark; Check whether the internal and external signs are consistent, especially whether the product itself has eye-catching signs and production dates.
2. Pay attention to the appearance of electric vehicle battery. Check for deformation, cracks, scratches and leakage marks. The battery terminals shall be clean and free from rust, and the signs shall be clear.
3. Pay attention to the rated capacity marked on the battery products of electric vehicles. The larger the rated capacity of the battery, the longer the battery discharge time. It is best not to buy batteries without rated capacity, but pay attention to whether they are special for electric vehicles.