Battery internal resistance refers to the voltage drop between the output voltage of the cells in the battery pack and the load current of the battery pack.
It is one of the important indicators of battery performance, which is directly related to the discharge capacity and cycle life of the battery.
So, how do you measure the internal resistance of a battery? I'll go into more detail below.
There are many ways to measure the internal resistance of a battery, among which the more commonly used are the AC internal resistance method and the DC internal resistance method.
Next, the two methods are parsed separately.
1. AC internal resistance method AC internal resistance method is a very commonly used method to measure the internal resistance of the battery, its principle is to measure the output voltage and load current of the battery by applying an AC signal to the battery, so as to calculate the internal resistance of the battery.
The specific steps are as follows:1Preparation: Select an AC power source and a waveform generator and connect them to the battery pack and load.
2.Apply AC signal: Through the waveform generator, the AC signal is applied to the battery pack.
3.Measure the output voltage: Use a voltmeter or oscilloscope to measure the output voltage of the battery pack.
4.Measure load current: Using an ammeter, measure the current through the load.
5.Calculating the internal resistance: Using the measured voltage and current data, the internal resistance of the battery is calculated using Ohm's law.
Second, the DC internal resistance method DC internal resistance method is also a commonly used method to measure the internal resistance of the battery, its principle is to measure the open circuit voltage and short circuit current of the battery by applying the DC signal, so as to calculate the internal resistance of the battery.
The specific steps are as follows:1Preparation: Select a DC power source and an ammeter and connect them to the battery pack and load.
2.Apply DC signal: Apply DC signal to the battery pack through DC power supply.
3.Measure the open-circuit voltage: Use a voltmeter or oscilloscope to measure the open-circuit voltage of the battery pack.
4.Measuring short-circuit current: Using an ammeter, measure the short-circuit current through the load.
5.Calculating the internal resistance: Using the measured voltage and current data, the internal resistance of the battery is calculated using Ohm's law.
In addition to the above two commonly used methods, there are some other methods to measure the internal resistance of the battery, such as through the charge-discharge curve method, the motor measurement method, etc.
These methods also have certain applicability in specific application scenarios.
To sum up, measuring the internal resistance of the battery is one of the important means of battery performance evaluation and fault diagnosis.
With a suitable measurement method, the internal resistance of the battery can be obtained to evaluate the quality and life of the battery.
However, it should be noted that different types of batteries (such as lead-acid batteries, lithium-ion batteries, etc.) and different working conditions may have different measurement methods and parameter settings, which need to be selected according to the actual situation.
I hope the above content is helpful to you in the measurement of battery internal resistance, thank you for reading.