Battery internal resistance measurement method 1Introducing the concept of battery internal resistanceBattery internal resistance refers to the degree of obstruction of the flow current inside the battery, which is one of the important indicators to measure the performance and quality of the battery.
Normally, the internal resistance of the battery will increase with the change of service life, which will have an impact on the discharge performance and power output capacity of the battery.
2.Commonly used methods for measuring the internal resistance of the battery (1) Constant current method to measure the internal resistance: This is a common measurement method that measures the voltage drop of the battery by adding a constant current at both ends of the battery, and calculates the internal resistance of the battery according to Ohm's law.
This method requires the use of specialized battery internal resistance test instruments, which can be improved by increasing the current to measure the accuracy.
2) AC method to measure internal resistance: This method calculates the internal resistance by adding an AC signal at both ends of the battery to measure the phase difference between the current and voltage of the battery.
This method allows testing under normal use without removing the battery from the device.
3) Electrochemical impedance spectroscopy to measure internal resistance: This is a more accurate measurement method, which needs to be tested with an electrochemical impedance spectroscopy instrument.
In this method, the internal resistance of the battery is derived by applying a series of AC signals to measure the current and voltage response of the battery.
3.Example Test StepsThe following is an example of the steps of a battery internal resistance test: (1) Connect the battery to be tested to the battery internal resistance measuring instrument to ensure that the connection is secure.
2) Select the appropriate measurement method, such as constant current method or AC method, and set the appropriate test parameters.
3) Start the measuring instrument and start measuring.
4) Observing the measurement results, the internal resistance value of the battery, as well as the accuracy and stability of the measurement, can be obtained.
5) Evaluate the state of health and performance of the battery based on the measurement results.
4.Other related contents: (1) The magnitude of the internal resistance of the battery will affect the discharge characteristics and storage capacity of the battery.
The greater the internal resistance, the lower the discharge time and power output capability of the battery.
2) The change of battery internal resistance is usually a manifestation of battery aging, and may also be affected by factors such as temperature and current.
3) For products that need to use the battery for a long time, measuring the internal resistance of the battery can help users judge the life and reliability of the battery.
4) Regularly measuring the internal resistance of the battery and maintaining it can prolong the service life of the battery and improve the performance of the product.
Through the above methods and steps, we can effectively test the internal resistance of the battery and obtain an evaluation of the performance and quality of the battery.
Understanding the internal resistance of a battery helps users select and use batteries and ensures the reliability and performance of the product.