What’s the difference between 18650, 26650 & 21700 batteries?

Understanding the Differences Between 18650, 26650, and 21700 Lithium Batteries: Applications and Suitability

As a lithium battery manufacturer, it is essential to recognize the differences between various lithium battery form factors and their applications. This article will explore the differences between 18650, 26650, and 21700 lithium batteries, discuss their typical applications, and explain why specific applications may prefer one battery type over the others.

  1. Battery Specifications and Dimensions: The main difference between 18650, 26650, and 21700 lithium batteries lies in their dimensions:
  • 18650: These batteries have a diameter of 18mm and a length of 65mm. They are the most common form factor for rechargeable lithium-ion batteries, with a typical capacity range of 1,800mAh to 3,500mAh.
  • 26650: These batteries have a larger diameter of 26mm and a length of 65mm. They offer higher capacities, typically ranging from 4,000mAh to 5,500mAh.
  • 21700: These batteries have a diameter of 21mm and a length of 70mm. They balance size and capacity, with typical capacities ranging from 3,000mAh to 5,000mAh.
  1. Applications: Each battery type has specific applications where used commonly, based on factors such as size, capacity, and performance.
  • 18650: Due to their widespread availability and smaller size, 18650 batteries are often used in applications such as laptops, portable power tools, electric vehicles, and e-bikes. They are also popular in flashlights, vapes, and various consumer electronics.
  • 26650: The larger capacity of 26650 batteries makes them suitable for applications requiring more power or longer runtimes, such as high-capacity power banks, solar energy storage systems, electric vehicles, and portable equipment with high energy demands.
  • 21700: The 21700 battery is a newer form factor that bridges the gap between the 18650 and 26650 batteries. Its increased capacity and size make it ideal for applications where both energy density and physical dimensions are critical, such as electric vehicles, drones, and portable electronics with high energy demands.
  • Why Choose One Battery Type Over Another: There are several reasons why an application may prefer one battery type over the others:

  • Size constraints: Smaller devices may require the compact form factor of a 18650 battery, while larger applications with more available space may opt for the higher capacity 26650 or 21700 batteries.
  • Capacity requirements: Applications with higher energy demands may benefit from the larger capacities offered by 26650 or 21700 batteries, while those with lower energy requirements may find the 18650 battery sufficient.
  • Weight considerations: The larger the battery, the heavier it is. Applications that prioritize weight, such as drones or portable electronics, may prefer the lighter 18650 or 21700 batteries.
  • Availability and cost: The widespread availability and lower cost of 18650 batteries may make them a more attractive option for some applications. However, as the 21700 battery becomes more popular, its availability and cost may also become more competitive.

Conclusion: Understanding the differences between 18650, 26650, and 21700 lithium batteries and their applications can help manufacturers and end-users decide which battery type is best suited for their needs. By considering factors such as size, capacity, weight & cost, it is available to choose the correct battery for each application and optimize the overall performance and efficiency of the device.