What is battery internal resistance? How to measure the internal resistance of a lead-acid battery?

　　Author ：Iflowpower – Færanleg rafstöð birgir

First, what is battery internal resistance? The internal resistance of the battery refers to the resistance of the battery when the battery is operating, which includes ohm internal resistance and polarized internal resistance, polarized internal resistance, including electrochemical polarized internal resistance and concentration polarization Block. The internal resistance of the battery is not a constant. It is constantly changing over time during the charge and discharge process, which is because the composition of the active material, the concentration and temperature of the electrolyte are constantly changing.

Omhene resistance complies with Ohm's law, the polarized internal resistance increases in current density, but is not linear relationship. Some logarithmial increases with current density. The internal resistance of the battery means that the battery is operating at the time of operation, which is generally divided into the interior of the battery, which is generally divided into AC internal resistance and DC internal resistance.

Since the internal resistance of the charging battery is small, the stream internal resistance is polarized due to electrode capacity , Germination polarized internal resistance, so it is impossible to measure the true cut value, and measure the impact of its communication internal resistance exemption to remove the internal resistance of the internal resistance. Second, lead-acid battery internal resistance measures: measure the ohmic resistance of lead-acid batteries to test the technical state of the battery, and the use of this method is increasingly popular. The internal resistance measurement of the battery contains several factors, including the content of the physical connection resistor, the electrolyte ion conductivity, and an electrochemical process that occurs on the surface of the plate.

About Polygonal batteries above 6 volts. The connection between the grid is also an additional impact on the detection value. The internal resistance of the battery can be detected by the following technique: a.

Impedance measurement can be applied to the lead-acid battery to apply a known frequency and amplitude current signal, and then measure the germination of the sprouting of the unit or the unit. The AC voltage is measured by the positive and negative terminals of the single battery or the minimum cell. Then use Ohm's law to calculate the impedance of this sprout, and the calculation is automatically completed by the instrument.

b .lectric conductivity can detect a change value of current over the battery by applying a known frequency and amplitude voltage on a battery, detecting a change value flowing over the battery, and the electrical conductivity is the ratio of the alternating component and voltage amplitude of the same phase. c.

Resistance measurement is to apply a load to the lead-acid battery, then measure the voltage and current flowing through the various stages of the battery. The ohmic value is the change rate of the use of voltage divided by the change rate of the current. d.

Open circuit voltage method, open circuit voltage method is to estimate the internal resistance of the lead-acid battery, the accuracy is poor, and even the error conclusion. Because even if a capacity has become small battery, the end voltage may still be normal in the floating state.