1. In the low temperature state, if the temperature is below 0 ℃, the internal resistance will increase by about 15% every time the temperature drops by 10 ℃. One of the important reasons is that the specific resistance is increased because the viscosity of sulfuric acid solution in the battery becomes larger.
At a higher temperature, such as 10 ℃ or above, the diffusion rate of sulfate ion increases, the concentration polarization effect decreases significantly, and the polarization resistance decreases, but the conductor resistance increases with the increase of temperature, but the rate of increase is small.
2. During the charging and discharging process of the battery, the resistance changes. The internal resistance changes from large to small during the charging process, and vice versa.
3. The internal resistance of thin plate battery is obviously smaller than that of thick plate battery, because the number of thin plates of the same capacity battery is more than that of thick plate battery, so when the same current is discharged, the current density of thin plate battery is small, and the polarization of each pole is much smaller.
4. Discharge current
In the instantaneous high current discharge, due to the rapid dilution of sulfuric acid solution in the plate gap, more than 90% of sulfuric acid molecules in the solution outside the plate hole have no time to diffuse into the plate gap. In this way, the specific resistance of the solution in the battery plate hole increases and the terminal voltage decreases significantly. However, after the discharge is stopped, the specific resistance of the solution in the plate hole decreases and the terminal voltage rises as the sulfuric acid molecules with high concentration diffuse into the plate gap.