How to measure battery internal resistance
The internal resistance of the battery is one of the important indicators to measure the performance of the battery. It directly affects the discharge capacity and service life of the battery. This article will introduce the measurement method of battery internal resistance in detail, and provide you with practical technical guidance based on hot topics and hot content on the entire network in the past 10 days.
1. Basic concept of battery internal resistance
The internal resistance of the battery refers to the obstruction to the flow of current inside the battery, which usually includes ohmic internal resistance and polarization internal resistance. The smaller the internal resistance, the better the performance of the battery. The following are common ranges of battery internal resistance:
| Battery type | Internal resistance range (mΩ) |
|---|---|
| Lead acid battery | 1-10 |
| Lithium-ion battery | 0.5-5 |
| NiMH battery | 5-20 |
2. Measuring method of battery internal resistance
Commonly used methods to measure battery internal resistance are as follows:
1. DC discharge method
By applying a known DC load to the battery, the voltage drop is measured, and the internal resistance is calculated based on Ohm's law. The formula is:Internal resistance = (no-load voltage - load voltage) / discharge current.
2. AC impedance method
Use an AC signal source to apply a small amplitude AC signal to the battery, and measure the phase difference between the voltage and current to calculate the internal resistance. This method is more accurate, but requires special equipment.
3. Special internal resistance tester
There are many dedicated battery internal resistance testers on the market, which are simple to operate and suitable for quick measurements. The following is a comparison of several common testers:
| Tester model | Measuring range | Accuracy |
|---|---|---|
| FlukeBT510 | 0.1-1000mΩ | ±1% |
| Hioki BT3561 | 0.1-3000mΩ | ±0.5% |
| Megger BITE3 | 0.01-2000mΩ | ±0.2% |
3. Precautions for measuring battery internal resistance
1.Safety first: Make sure the battery is in a stable state when measuring to avoid short circuit or over-discharge.
2.ambient temperature: The internal resistance of the battery is greatly affected by temperature. It is recommended to measure it in an environment of about 25℃.
3.Equipment calibration: Regularly calibrate test equipment to ensure the accuracy of measurement results.
4. The relationship between hot topics on the Internet in the past 10 days and battery internal resistance
Recently, the rapid development of new energy vehicles and energy storage technology has made battery performance testing a hot topic. The following are hot topics related to battery internal resistance in the past 10 days:
| topic | heat index | Related content |
|---|---|---|
| New energy vehicle battery health testing | ★★★★★ | Internal resistance measurement as an important indicator of battery health |
| Safe operation and maintenance of energy storage power stations | ★★★★ | Abnormal internal resistance warns of potential battery failure |
| Electric vehicle range declines in winter | ★★★ | The impact of changes in internal resistance on battery life in low temperature environments |
5. Summary
The measurement of battery internal resistance is an important means to evaluate battery performance. Whether it is routine maintenance or professional testing, it is crucial to master the correct measurement method. Through the introduction of this article, I hope you can better understand the measurement principles and methods of battery internal resistance and achieve better results in practical applications.
If you have other questions about battery internal resistance measurement, please leave a message in the comment area to discuss!
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