Lithium battery capacity explanation

Lithium battery capacity refers to the amount of electricity that the battery can give under certain discharge conditions. It is usually expressed by C, and the unit is Ah or MAH. Capacity is an important indicator of battery electrical performance. Lithium battery capacity is usually divided into rated capacity, actual capacity and theoretical capacity. The capacity of the lithium battery is determined by the capacity of the electrode, especially the positive electrode material. By improving the performance of the positive electrode material, the capacity of the lithium battery can be greatly increased, and the volume of the battery can be reduced.

Rated capacity (rated capacity) refers to the lithium battery capacity indicated by the lithium battery manufacturer. The GB/T18287-2000 standard proposed by the Ministry of Information Industry of the People's Republic of China stipulates that the rated capacity of the lithium battery means that the battery is at an ambient temperature of 20 ± 5 °C. The amount of electricity that should be supplied when discharging at a rate of 5h to the end voltage is expressed in C5, in units of Ah (ampere-hours) or MAH milliampere hours.

The actual capacity refers to the amount of electricity that a lithium battery can output under certain conditions. It is equal to the product of the discharge current and the discharge time in MAH, which is less than the theoretical capacity.

The theoretical capacity is the highest theoretical value calculated by calculating the mass of the active material according to Faraday's law. In order to compare different series of batteries, the concept of specific capacity is commonly used, that is, the theoretical amount of electricity that can be given per unit volume or unit mass of battery, in units of Ah/kg (MAH/g) or Ah/L (MAH/cm3). The specific capacity of a lithium battery is high, such as a lithium cobaltate material having a specific capacity of 135 - 140 MAH/g.

Lithium battery capacity is divided into lithium battery capacity and finished lithium battery capacity. The capacity of 18650 lithium battery cells is generally 1000~2800mAh, while the capacity of finished lithium batteries ranges from several hundred milliamperes to tens of amps. Lithium battery capacity = lithium battery capacity * parallel battery number, such as 2 The capacity of the 186502200mAh lithium battery cells in parallel = 2200mAh*2 = 4400mAh.

Many informal manufacturers will falsely standard lithium battery capacity, deceive consumers, especially some mobile phone batteries. The market so-called mobile phone large capacity lithium battery is basically a business under the guise of, therefore, we should pay attention to identify the lithium battery capacity when we choose and buy lithium battery.

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