Refers to the resistance of current flowing through the battery when the battery is working. It consists of two parts: ohmic internal resistance and polarized internal resistance. High battery internal resistance reduces the battery discharge voltage and reduces the discharge time. The internal resistance is mainly affected by battery material, manufacturing process, battery structure and other factors. It is an important parameter to measure battery performance. Note: Generally, the internal resistance of charging state is the standard. To measure the internal resistance of the battery, use a dedicated internal resistance meter instead of a multimeter in ohm gear.