21700 Single cell capacity

What is a 21700 battery?

The 21700 battery is a cylindrical lithium-ion battery with a diameter of 21mm and a length of 70mm. It offers a nominal voltage of 3.7V and a capacity of up to 5,000mAh, making it a powerful and efficient energy source. Its energy density ranges between 250 Wh/kg and 300 Wh/kg, depending on the chemistry.

How big is a 21700 cell?

The 21700 cell stands out due to its standardized dimensions of 21mm in diameter and 70mm in length. These measurements make it larger than the widely used 18650 cell, which measures 18mm by 65mm. This increase in size allows the 21700 to deliver higher energy storage and improved performance.

Why is a 21700 cell a good choice?

The larger size of the 21700 cell enables it to store more energy, making it ideal for applications requiring high power capacity, such as electric vehicles and industrial battery packs. Its dimensions also contribute to better thermal management, ensuring safer and more efficient operation.

How many Mah does a 21700 cell hold?

At its core, a single 21700 cell usually holds 4000–5000 mAh with a nominal voltage of 3.6–3.7 V. Fully charged, it hits 4.2 V, and cutoff usually happens around 3.0 V. In practice, I’ve seen these cells hold up better under high current draw compared to 18650. Less heat, less sag, and more usable runtime.