With the development of society, energy storage lithium batteries occupy an increasingly important position in society. As of the end of 2015, China's energy storage capacity was 22.8GW, accounting for 1.7% of the country's total installed power. It is estimated that by 2025, the energy storage lithium battery industry will achieve large-scale development and form a relatively complete industrial system, which will become a new economic growth point in the energy sector. At present, there are three major application areas in the energy storage lithium battery market: power storage, household energy storage, and base station energy storage. The backup power supply field of communication base stations currently accounts for a large proportion, accounting for nearly half of the entire energy storage lithium battery market. Share. The capacity of a lithium battery is a prerequisite for how long the device can be used. So friends know how to measure lithium battery capacity is more accurate? There is a certain deviation between the nominal capacity and the actual capacity of the general manufacturer. To understand the steps of the 18650 lithium battery capacity measurement method, let's learn together.

Simple method of constant resistance discharge. Need to use a multimeter and high-power resistors, first full, you can be on the charger, such as on the phone, on the phone. Connect the battery to the load and connect it to this resistor. Usually it can be 10 ohms and 5W of cement resistor for discharge discharge until the voltage is lower than 2.75V. The total discharge time capacity is 0.37A*. This method is simple, but there is a certain error. .

Regular method: use the battery capacity tester, first charge to 4.20V, and then set a constant current discharge for 1 hour. The arbitration method is to discharge at a constant current of 200mA to 2.75V cutoff at a 0.2x rate, such as 1000mAh capacity. Calculate the time and time. * Constant current = battery capacity This is done in accordance with the national standard 18287 lithium battery regulations. If it is a nickel-metal hydride battery, the same reason, only the charging method is not constant voltage, and the discharge is up to 1.0V per section. This method requires special equipment.

method one:

Professional battery compartment

If it is an individual, find an adjustable adjustable load resistor and a current-adjustable DC power supply to calculate the battery capacity by charging and discharging time. Charging current × charging time = battery capacity (charge from 2.7V or 3.0V) To 4.2V) or discharge current × discharge time = battery capacity (discharge from 4.2V to 2.7V or 3.0V)

Method 2: Fully charge the battery to the rated voltage, generally 4.2V

The second step is to discharge the battery, reach the rated voltage, and record how much power is discharged. The voltage is generally 3.0V.

The third step is to charge the battery to a normal amount, which is generally set to 3.8V-4.0V.

The capacity recorded in the second step is the capacity of the battery.

Method three:

Using the integral function of the power meter can measure the lithium battery capacity required by the device. I usually use the power meter of the PA310 to measure the lithium battery capacity. After measuring the capacity, select the battery larger than the capacity for the device to use.

The 18650 lithium battery capacity measurement method steps are as above. Under normal circumstances, the capacity of the 18650 battery will not exceed 3100mAh (the limit is 3400mAh, any excess is fake goods, there is a danger of explosion. The author is buying a high-light flashlight with a battery of 5000mAh, right, small Are the partners stunned? It is obviously a virtual standard).

Standard for 18650 lithium-ion battery

Why is the application of 18650 batteries so popular? A key reason is standardization. Of course, chemical formulations, internal structures, and manufacturing methods have evolved over the past 20 years to produce batteries with better performance and longer cycle times. What has not changed is the size of the battery.

The 18650 battery has a diameter of 18 mm and a height of 65 mm; therefore, its name is 18650.

Other battery formats are also available in standard sizes, but although they are standardized, many alternative battery designs do not reach the same prevalence of the 18650 and are hard to be called standards.

Conversely, as more and more applications use 18650 batteries, the 18650 has become one of the most popular battery sizes and is clearly a global standard. Many battery manufacturers offer batteries of this size when batteries are used in large quantities. This also drives competition, especially in terms of cost, as well as a wide variety of sources and a wide range of product quality.

18650 batteries are usually chosen due to good energy density and reasonable size and capacity. Therefore, once the battery is selected, the mechanical engineer can design a battery holder or battery pack to accommodate one or more 18650 batteries.

If the battery is a 18650, because it is a standard size, mechanical engineers can design the device to accommodate any supplier's battery. Then, the engineer can consider the price, delivery, and unit performance of each battery manufacturer in the application to select the best 18650 unit. .