21700 vs 18650 Batteries: Which Reigns Supreme?

If you frequently use rechargeable batteries, you’ve likely heard of the 18650 and 21700 battery types. These two types of lithium-ion batteries are popular choices for various applications, including flashlights, e-cigarettes, and electric vehicles. But when it comes to choosing between the two, which is better? This article will examine the differences between 18650 and 21700 batteries and help you decide which suits your needs.

Introduction

Rechargeable batteries are essential to our daily lives, powering everything from smartphones to electric vehicles. The two most popular types of lithium-ion batteries are the 18650 and 21700 batteries. Both types have unique advantages and disadvantages, and the decision between them ultimately depends on your specific needs.

What are 18650 batteries?

Cylindrical lithium-ion batteries that are 18mm in diameter and 65mm in length, hence the name 18650, have been around for over two decades and people commonly use them in various applications, including laptops, flashlights, and electric vehicles.

What are 21700 batteries?

21700 batteries are newer cylindrical lithium-ion batteries that are 21mm in diameter and 70mm in length. They were first introduced in 2015 and have gained popularity recently due to their higher capacity and improved performance over 18650 batteries.

21700 VS 18650 batteries

Size comparison

One of the most apparent differences between 18650 and 21700 batteries is their size. As mentioned earlier, 18650 batteries are 18mm in diameter and 65mm in length, while 21700 batteries are 21mm in diameter and 70mm in length. This means that 21700 batteries are slightly larger and heavier than 18650 batteries.

Capacity comparison

Capacity is another important factor when choosing between 18650 and 21700 batteries. 21700 batteries typically have a higher capacity than 18650 batteries due to their larger size. For example, a typical 18650 battery has a capacity of around 3000mAh, while a 21700 battery can have a capacity of up to 5000mAh or more.

Voltage comparison

Voltage is another essential consideration when choosing between 18650 and 21700 batteries. Both types of batteries have a nominal voltage of 3.6V, but the actual voltage can vary depending on the specific battery and application.

Discharge rate comparison

The discharge rate refers to how quickly a battery can release its energy. 21700 batteries typically have a higher discharge rate than 18650 batteries due to their larger size and improved design. This makes them a better choice for high-drain applications such as electric vehicles and power tools.

Charging time comparison

Charging time is another critical factor when choosing between 18650 and 21700 batteries. Generally speaking, 21700 batteries can be charged faster than 18650 batteries due to their larger size and improved design. However, the charging time can vary depending on the battery and charger used.

Price comparison

Price is always an important consideration when it comes to purchasing batteries. Generally speaking, 18650 batteries are more affordable than 21700 batteries due to their smaller size and long history in the market. However, the price difference between the two types of batteries can vary depending on the specific brand and capacity.

Application Comparison

The specific application in which the battery will be used is a crucial factor to consider when choosing between 18650 and 21700 batteries. 18650 batteries are popular for applications such as flashlights, laptops, and e-cigarettes, while 21700 batteries are often used in high-drain applications such as electric vehicles and power tools.

Pros and cons of 18650 batteries

• Pros:
  • Affordable
  • Widely available
  • Good for low-drain applications
• Cons:
  • Lower capacity and discharge rate compared to 21700 batteries
  • Longer charging time compared to 21700 batteries

Pros and cons of 21700 batteries

• Pros:
  • Higher capacity and discharge rate compared to 18650 batteries
  • Faster charging time compared to 18650 batteries
  • Better for high-drain applications
• Cons:
  • More expensive than 18650 batteries
  • Not as widely available as 18650 batteries

Which battery should you choose?

Choosing between 18650 and 21700 batteries ultimately depends on your specific needs and the application in which the battery will be used. If you’re looking for an affordable battery for low-drain applications such as flashlights and e-cigarettes, 18650 batteries are a good choice. However, if you need a higher capacity and discharge rate for high-drain applications such as electric vehicles and power tools, 21700 batteries are the better choice.

Conclusion

In conclusion, 18650 and 21700 batteries have unique advantages and disadvantages. When choosing between the two, it’s essential to consider factors such as capacity, discharge rate, charging time, and application. Ultimately, the decision between 18650 and 21700 batteries depends on your specific needs and the application for the battery.

FAQs

Are 21700 batteries better than 18650 for electric vehicles?

• Yes, 21700 batteries are generally better than 18650 batteries for electric vehicles due to their higher capacity and discharge rate.

Can I use a 21700 battery in a device designed for 18650 batteries?

• It depends on the specific device and battery. Some devices may be compatible with both types of batteries, while others may only support one type.

Do 21700 batteries have a longer lifespan than 18650 batteries?

• The lifespan of a battery depends on several factors, including usage and storage conditions. Generally speaking, both 18650 and 21700 batteries have similar lifespans.

Are 21700 batteries worth the extra cost?

• The answer to this question depends on your specific needs and the application in which the battery will be used. If you require a battery with a higher capacity and discharge rate for high-drain applications such as electric vehicles and power tools, the extra cost of 21700 batteries may be worth it. However, suppose you’re using the battery for low-drain applications like flashlights and e-cigarettes. In that case, the cost difference between 18650 and 21700 batteries may not be significant enough to justify the upgrade.

Can I mix and match 18650 and 21700 batteries in the same device?

• Mixing and matching different types of batteries in the same device is not recommended. This is because different batteries may have different capacities and discharge rates, resulting in imbalanced power delivery and potentially damaging the batteries or device.