What is a 21700 battery?

A 21700 battery is a rechargeable lithium-ion cell with a cylindrical shape and standardized dimensions of 21mm in diameter and 70mm in length.

Are 21700 batteries safe?

Unprotected 21700 batteries: Lack built-in safety features and are generally used in battery packs with external battery management systems (BMS). 21700 batteries are widely used in: Electric vehicles, with companies like Tesla and other manufacturers using them in battery packs for improved energy storage and performance.

What is the difference between protected and unprotected 21700 batteries?

Protected 21700 batteries: Feature an internal protection circuit to prevent overcharging, over-discharging, and short circuits, making them slightly longer than 70mm. Unprotected 21700 batteries: Lack built-in safety features and are generally used in battery packs with external battery management systems (BMS). 21700 batteries are widely used in:

What is a 21700 cell?

21700 cell, as the name suggests, stands for a cylindrical cell with 21mm width and 70mm height. It was first introduced in 2017 by a Tesla and Panasonic collaboration. 21700 was introduced as an alternative to the long-running 18650 model, which was introduced by Sony in 1991.

How much power does a 21700 mAh battery hold?

You don’t really notice the size increase, but you definitely feel the performance upgrade. 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.

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.