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What is the capacity of the battery?

2022-01-25 16:07

1、What is the capacity of the battery?

Refers to the electric energy that can be released by the active substances in the battery when they take part in electrochemical reaction, which is called the capacity of the battery, that is, how much charge the battery can hold after charging. The unit is 'ampere hour' (Ah). When discharging for 1 hour at a current of 1 ampere (A), the capacity of 1 ampere hour (Ah) is obtained. Assuming that the average current is 4A, when discharging at the terminal voltage of the battery, the discharge time lasts for 3 hours. The capacity of the battery is 12Ah (discharge efficiency is not calculated here).

Lithium battery

2. What is the rated capacity of the battery?

The rated capacity of the battery refers to the design and manufacture of the battery, which stipulates or guarantees that the battery should discharge the minimum amount of electricity under certain discharge conditions. The battery capacity indicated by the manufacturer refers to the amount of electricity that should be provided when the battery is discharged to the termination voltage at the rate of 2h at the ambient temperature of 25℃, which is expressed by C2 and the unit is Ah (ampere hour).


3. What is the design capacity of the battery?

According to the amount of active materials contained in the battery, the capacity of the battery calculated from the electrochemical theory is called the design capacity.


4、What is the actual capacity of the battery?

The actual capacity of the battery refers to the actual power discharged by the battery under certain discharge conditions, which is mainly influenced by the discharge rate and temperature (so strictly speaking, the battery capacity should indicate the charge and discharge conditions).


lead-acid battery

BETTER : Battery Manufacturing 4P Service Standard Pioneer


5、What is the classifying capacity of the battery?

In the manufacturing process of batteries, the actual capacity of batteries can't be completely consistent due to technological reasons. The process of classifying batteries according to capacity is called classifying capacity, which is detected by a certain charging and discharging system.


6、What is the capacity labeling method of lead-acid batteries for electric vehicles?

C2 shall prevail, that is, discharge at 0.5C2 current. When the voltage reaches the cut-off discharge voltage of the battery, the product of discharge time and current shall be equal to or close to the rated capacity value. For example, a 12V, 12Ah battery is discharged at 5A current, and when the cut-off discharge voltage reaches 10.5V, the time cannot be less than 140min; Similarly, a 12V, 10Ah battery is discharged at 5A current until the voltage reaches the cut-off discharge voltage of 10.5V,The time cannot be less than 120min. The error is 0.1Ah


In fact, the industry standard stipulates that the discharge time of 10Ah battery to the cut-off discharge voltage at 5A current should not be less than 120min. The actual product reached by the enterprise is 130~137min.


7、What are the marking methods of lead-acid battery capacity at present?

At present, there are several marking methods for the capacity of lead-acid batteries, such as C20, C10, C5 and C2, which respectively represent the actual capacity obtained when discharging at the discharge rates of 20h, 10h, 5h and 2h. If it is the capacity at a discharge rate of 20 hours, the label should be C20,C20=10Ah battery, which refers to the capacity value obtained by discharging at a current of C20/20 for 20 hours. Converted to C5, that is, discharged at four times of C20 specified current, the capacity is only about 7Ah.Generally, the electric bicycle will discharge at a high current within 1~2h, and the lead-acid battery will be discharged within 1~2h(C1~C2), which is close to 10 times of the specified current, so the electric energy it can actually supply is only 50% ~ 54% of C20 discharge capacity. The battery capacity is marked C2, that is, the capacity marked at the rate of 2h discharge. If it is not C2, it should be calculated to get the correct discharge time and capacity. If the capacity indicated by 5h discharge rate (C5) is 100%, the actual capacity is only 88% if it is discharged within 3h instead. After 2 hours, only 78%; after discharging in 1 hour, only 65% of the capacity when discharging in 5 hours remains. If the marked capacity is 10Ah, only 8.8Ah of actual electricity can be obtained by discharging at 3 hours; If it is discharged for 1 hour, only 6.5Ah of electricity can be obtained, and the discharge rate can be arbitrarily reduced, the discharge current is greater than 0.5C2 not only reduces the capacity than indicated, but also has a certain influence on the battery life. Similarly, for the battery marked (rated) as C3, the discharge current is C3/3, that is, ≈0.333C3, if it is C5, the discharge current should be 0.2C5, and so on.


8、Why should the battery be stored for some time before it can be packaged and shipped?

The storage performance of the battery is an important parameter to measure the stability of the comprehensive performance of the battery. After a certain period of storage, the capacity and internal resistance of the battery are allowed to change to a certain extent. After a period of storage, the electrochemical performance of internal components can be stabilized, and the self-discharge performance of the battery can be known. So as to ensure the quality of the battery.


"Good quality battery need good equipment", Better Technology Group Limited, which is mainly specialize in lead acid battery production equipment, raw materials and spare parts.  Focused on development for over ten years,With rich experience in battery manufacturing and mechanical manufacturing in the lead-acid battery industry, takes the lead in productizing solutions,Adhering to high-end equipment and high-quality services, It is a rare manufacturer which a battery Manufacturing Solution Expert and Resource-rich Operator. We  has created “China's First Station” and became the "Purchasing Center in China" for many international customers, Has thoroughly solved problems including the long project construction period, the heavy technical connection task, unreasonable production line matching, and cumbersome business communication arising from purchasing from multiple sources by customers.


Now, Better Technology Group Limited owns two major brands, BETTER and WELLPACK, which are mainly engaged in lead acid battery and lithium battery respectively and create professional connection between lead acid battery resources and lithium battery.  The company not only provides customers with equipment, batteries, raw materials, auxiliary materials, related accessories, battery production technology output and other related businesses, but also focuses on the research, development, production and sales of various high-end lithium ion batteries, as well as the development of diversified customized lithium battery application solutions.  The application scope covers consumer electronics, toys, power tools, automobiles, electric vehicles, energy storage systems and other fields.  

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