Cylindrical lithium-ion cells are typically represented by five digits. Counting from the left, the first two digits indicate the battery diameter, the third and fourth digits indicate the battery height, and the fifth digit indicates that the cell is circular. There are many models of cylindrical lithium batteries, with common ones including 10400, 14500, 16340, 18650, 21700, 26650, and 32650.
1. 10440 battery
The 10440 battery is a lithium battery with a diameter of 10mm and a height of 44mm, the same size as what we commonly call a "size 7 battery". This type of battery generally has a very small capacity, only a few hundred mAh, and is mainly used in mini electronic products, such as flashlights, mini speakers, and megaphones.
2. 14500 battery
The 14500 battery is a lithium battery with a diameter of 14mm and a height of 50mm. This type of battery is generally 3.7V or 3.2V, with a relatively small nominal capacity, slightly larger than the 10440 battery, usually 1600mAh. It has excellent discharge performance and is mainly used in consumer electronics, such as wireless speakers, electric toys, and digital cameras.
3. 16340 battery
The 16340 battery is a lithium battery with a diameter of 16mm and a height of 34mm. Because of its relatively short height and relatively large capacity, this type of battery is frequently found in high-powered flashlights, LED flashlights, headlamps, laser lights, and other lighting fixtures.
4. 18650 battery
The 18650 battery is a lithium battery with a diameter of 18mm and a height of 65mm. Its biggest feature is its very high energy density, which is almost 170 Wh/kg. Therefore, this type of battery is a cost-effective battery. Most of the batteries we see in daily life are of this type because it is a relatively mature lithium battery with good system quality and stability in all aspects. It is widely used in battery capacity applications of around 10 kWh, such as in mobile phones, laptops and other small electronic devices.
5. 21700 battery
The 21700 battery is a lithium battery with a diameter of 21mm and a height of 70mm. Due to its increased size, the space utilization rate is improved, and the energy density of individual cells and the system can be increased. Its volumetric energy density is much higher than that of the 18650 battery. It is widely used in digital products, electric vehicles, balance vehicles, solar-powered lithium battery street lights, LED lights, power tools, etc.
6. 26650 battery
The 26650 battery is a lithium battery with a diameter of 26mm and a height of 65mm. It has a nominal voltage of 3.2V and a nominal capacity of 3200mAh. This type of battery has excellent capacity and high consistency, and it has gradually become the replacement for the 18650 battery. Many products in the field of power batteries will also gradually favor this type.
7. 32650 battery
The 32650 battery is a lithium battery with a diameter of 32mm and a height of 65mm. This type of battery has a strong continuous discharge capability, making it suitable for electric toys, backup power supplies, UPS batteries, wind power generation systems, and wind-solar hybrid power generation systems.
