What harm does excessive discharge of electric vehicles do to the battery?

During the discharge process of the battery, the positive active material and negative active material are gradually transformed into PbSO4 with high resistance, and the sulfuric acid in the electrolyte is consumed, and the internal resistance increases gradually

Therefore, during over discharge, especially at a large current, a large amount of heat will be emitted, and the amount of sulfuric acid in the battery is very small

During overdischarge, the concentration of sulfuric acid decreases very low and the solubility of PbSO4 increases greatly

Therefore, it is easy to form a thick and hard PbSO4 crystal on the electrode plate, that is, "irreversible sulfation", which greatly weakens the charging acceptance capacity of the battery and is particularly harmful.