Introduction to High Rate 18650 Battery Life and Quality Testing Methods.
High rate battery life testing, high rate battery quality testing methods. High rate batteries are widely used in high-tech products, such as model drones, intelligent robots, military supplies, etc. Therefore, high rate batteries are also a product that requires high quality and high safety. However, many consumers are often unclear about the performance and testing methods of batteries when using them. The service life of high-quality batteries is about two to three years, while high rate batteries are not durable due to their fast power consumption and reduced charging time. In order to ensure the safe use of high rate batteries, we should take good care of battery protection.
Testing method for high rate battery life
High rate battery life testing mainly tests the number of charge and discharge cycles of lithium batteries when the available capacity drops to the permitted value. The specific testing steps are as follows:
1. High rate batteries are discharged at a constant current of 0.2C to the specified termination voltage (usually 3.0V) at an ambient temperature of (20 ± 5) ℃, and then charged at a constant current of 0.2C to the termination voltage (usually 4.2V) before switching to constant voltage charging (charging termination current is usually 0.02C);
2. High rate batteries are discharged at a constant current of 0.2C at an ambient temperature of (20 ± 5) ℃ to the specified discharge termination voltage;
3. High rate batteries are cycled at an ambient temperature of (20 ± 5) ℃, and the battery is left for no more than 1 hour between charging and discharging or between discharging and charging;
4. High rate batteries should be discharged and charged in cycles according to steps 1 and 2 until the discharge capacity is below 70% of the rated capacity.
Testing method for high rate battery quality
1. The fastest way to test the quality of high rate batteries is to measure their internal resistance and maximum discharge current. High quality batteries have relatively low internal resistance and a large maximum discharge current. A multimeter with a range of 20A is used to short-circuit the two electrodes of a lithium battery application. The current should generally be around 10A or even higher, and it can be maintained for a period of time. A relatively stable battery is considered a good battery.
2. Appearance inspection. The degree of fullness in appearance, such as a high rate battery with a rated capacity, which is relatively large in size, finely crafted, or has a fuller packaging.
3. Hardness testing. You can gently or moderately pinch the middle part of the battery with your hand. If the hardness is moderate and there is no soft squeezing sensation, it proves that the battery cell belongs to a relatively high-quality battery cell.
4. Weight testing. Remove the outer packaging and check if the battery weight is relatively heavy. If it is heavy, it belongs to high-quality battery cells.
5. During the charged operation of high rate batteries, if the two poles of the battery do not heat up after about 10 minutes of continuous discharge, it proves that the battery protection board system is complete. Generally, batteries with high-quality protection boards have better quality than ordinary batteries.
How to check the quality of the battery protection board?
The main function of the battery protection board is to provide charge and discharge protection for the series connected battery pack; When fully charged, it can ensure that the voltage difference between each individual battery is less than the set value (generally ± 20mV), achieving uniform charging of each individual battery in the battery pack and effectively improving the charging effect under series charging mode; Simultaneously detecting the overvoltage, undervoltage, overcurrent, short circuit, and overheating status of each individual battery in the battery pack, protecting and extending the battery's service life; Under voltage protection prevents each individual battery from being damaged due to over discharge during discharge use.
1. Confirm the correct wiring of the battery cable through a multimeter;
2. After measuring the voltage to be normal, plug the cable into the protection board and measure the resistance between B - and P - of the protection board. If the resistance is 0, it means that they were unobstructed before and the battery protection board is good.
3. By connecting the B-line, the voltage of B - and the total positive terminal of the battery can be measured, as well as the voltage of P - and the total positive terminal of the battery. If the voltage is consistent, it indicates that the protection board is normal. If two voltages are consistent, it indicates that the protection board is normal. If P - discharges through high current, there will be a slight voltage drop and the protective plate will heat up (around 50 degrees), which is a normal phenomenon.
Check whether the high rate battery meets the prescribed safety standards
1. Squeeze vigorously. Place the fully charged battery under test on the testing plane of the testing machine, then apply a squeezing force of 13+1KN with an hydraulic cylinder, and finally squeeze the battery with a steel rod plane with a diameter of 32mm. If the battery can withstand the maximum pressure without explosion or fire, it indicates that the battery product is qualified.
2. Heavy object impact. After fully charging the tested battery, place it on the testing plane of the testing machine, vertically place a steel column with a diameter of 15.8mm at the center of the battery, and freely drop a weight of 9.1kg from a height of 610mm onto the steel column above the battery. If the battery does not catch fire or explode, it means it is OK.
3. Overcharge test. The so-called overcharge test is actually to test whether the internal stability of a high rate battery is stable. The method is very simple. First, fully charge the battery with 1C, and then conduct an overcharge test according to 3C overcharge 10V. When the battery is overcharged, the voltage rises to a certain voltage and stabilizes for a period of time. When it approaches a certain time, the battery voltage rises rapidly. When it rises to a certain limit, the battery cap breaks and the voltage drops to 0V. If the battery did not explode or catch fire during this process, it indicates that the battery is a qualified product.
The above is all about "high rate battery life testing, high rate battery quality testing methods". With the advancement and innovation of technology, high rate batteries have also entered a rapid development and begun to be applied in various fields of our lives. After the production of high rate batteries, a series of tests need to be conducted before reaching consumers to ensure the safety of the batteries and reduce safety hazards as much as possible.
