The factors that affect the capacity of lead-acid batteries include the structure of the electrode plate, the size of the charge and discharge current, the temperature and density of the electrolyte, etc. Among them, the charge and discharge current and temperature have the greatest influence. If the charge and discharge current is too large, the active material on the plate will change to the surface, and the capacity will be greatly reduced.
    The discharge current of the battery is different, and the capacity that can be discharged is also different. The larger the discharge current, the smaller the amount of electricity that can be discharged. Evaluating the capacity of the battery depends not only on the nominal capacity of the battery, but also on the discharge rate of the battery.    
    The internal resistance of the battery refers to the resistance received when the current flows through the interior of the battery. The internal resistance of the lead-acid battery is very small, and it needs a special instrument to obtain a more accurate result. The battery repair instrument generally refers to the internal resistance of the battery. It is the internal resistance of the charging state, that is, the internal resistance of the battery when it is fully charged. Corresponding to it is the internal resistance in the discharge state, which refers to the internal resistance of the battery after the battery is fully discharged.
    Generally speaking, the internal resistance in the discharging state is larger than that in the charging state, and is less stable. inside the battery greater the resistance, the more energy is consumed by the battery itself, which makes it less efficient. A battery with a large internal resistance generates a lot of heat during charging, which makes the temperature of the battery rise sharply, which is harmful to the battery and the battery.

    The charger has a big impact With the increase in the number of times the battery is used. Due to the consumption of electrolytes.As well as the reduction of the activity of the chemical substances in the internal resistance of the battery, the internal resistance of the battery will occasionally vary.As the temperature increases, the worse the quality of the battery, the faster it grows.

    The impedance of the internal resistance of the battery will increase due to the increase of the discharge amount, especially when the discharge is terminated , if it continues to discharge, the lead sulfate will form a stable white crystal, even if it is charged, the active material of the plate will not be able to return to its original state, which will shorten the service life of the battery.