Power lithium battery as an important energy storage device, it is widely used in electric vehicles, unmanned aerial vehicles, energy storage systems and other fields. They have a variety of power specifications to meet the needs of different devices. The following are the commonly used power specifications and application fields of power lithium batteries:

1. 18650 battery
   18650 battery is a common lithium ion battery specification, with a diameter of 18mm and a length of 65mm, hence its name. This kind of battery usually has high energy density and cycle life, and is widely used in portable electronic devices, notebook computers, electric tools and other fields. Due to its moderate size, 18650 batteries are also widely used in electric vehicles and energy storage systems.

2. 21700 battery
   21700 battery is a new type of lithium ion battery specification rising in recent years, with a diameter of 21mm and a length of about 70mm. Compared with 18650 batteries, 21700 batteries have higher energy density and larger discharge power, so they are widely used in electric vehicles, electric tools and large-capacity energy storage systems.

3. 26650 battery
   26650 battery is a large lithium ion battery with a diameter of 26mm and a length of about 65mm, with high energy density and discharge power. Due to its large size, 26650 batteries are usually used in applications requiring large capacity and high power output, such as large electric tools, energy storage systems, special vehicles and other fields.

4. Soft Pack Battery
   soft Pack Battery is a kind of lithium ion battery without fixed shell. Its outer package is made of soft pack material, which can be flexibly designed as needed. Soft Pack batteries usually have lighter weight and higher energy density, so they have been widely used in portable electronic equipment, electric bicycles, balance cars and other fields.

5. Customized battery
   in addition to the above common specifications, power lithium batteries also have many customized specifications to meet the needs of specific equipment. These customized batteries are usually designed for specific power, energy density, size, safety and other requirements, and are widely used in high-end fields such as special vehicles, aerospace fields, medical equipment and so on.

Power Lithium batteries have a variety of commonly used power specifications, and each specification is optimized for different application fields and requirements. With the continuous progress of science and technology, I believe that more new lithium battery specifications will emerge as the times require in the future, providing more choices and possibilities for the development of various power equipment.