21700 Power tool lithium battery 20 strings

What is a 21700 battery pack?

If you’ve been around anything that runs on lithium batteries—whether it’s drones, e-bikes, power tools, or even flashlights—you’ve probably noticed the buzz around 21700 battery packs. The name comes from the size: 21 mm in diameter and 70 mm in length.

Is a 21700 Battery Worth It?

Sure, it’s pricier than a traditional 18650 setup, but the efficiency gain makes it worth it. Not all 21700 cells are built the same. Some are optimized for high capacity (great for long runtime), while others are tuned for high discharge rates (better for power-hungry tools or drones).

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.

Are all 21700 cells the same?

Not all 21700 cells are built the same. Some are optimized for high capacity (great for long runtime), while others are tuned for high discharge rates (better for power-hungry tools or drones). There’s a fun discussion I came across where hobbyists compared popular options.