PE battery separator has many effects on the performance of lead battery. Every improvement of separator quality is accompanied by the improvement of lead battery performance. The main function of PE battery separator is to prevent short circuit between positive and negative electrodes, but it cannot significantly increase the internal resistance of the battery. PE battery separator is mainly used to prevent short circuit between positive and negative electrodes, but it cannot significantly increase the internal resistance of the battery. Therefore, the separator should be porous, allowing free diffusion of electrolyte and ion migration, and has a relatively small resistance. PE battery separator shall not reach the opposite electrode plate through fine holes, that is, the hole diameter shall be small, the number of holes shall be large, and the total area of the gap shall be large.